I want to see what you guys can come up with for under $500.  Must be new parts available to any buyer..

Heres mine:
MEGA Lower:  $89 shipped off Iblis(sp?)
20" AR15 Standard Kit $400 from Model 1 (I dont have shipping numbers on the kit.. sorry)

$ 89.00
$400.00 (shipping cost?)
--------
$489.00

Can you beat that?

Iblis is a great guy to deal with, but unless you deal with him face to face, he needs to ship to a FFL.  The shipping and the FFL fee should run around $35 total, give or take a little.  The Model 1 kit is going to run you with shipping as well, probably another $15-20.  That puts you in the $545 range.  Why not ask what you can get for under $550 and make it realistic, better yet, make it under $600.

To answer your question, the cheapest I have built was all parts including the lower for under $200.  All parts were new, and I had to assemble everything myself.  The barrel is a stainless 20 " match, and the rifle looks like a postban A2.  I was in the right place at the right time and some good people took care of me.

nothing too great

shipping on the model 1 kits is around $18 to me, so YMMV.  My model 1 kit is fine...my only beef was the charging handle felt cheap; other than that, no complaints whatsoever.  500 rounds or so without a hiccup, so I'm happy. It goes bang when I pull the trigger, and I've shot a fluke sub moa group with it using fmj ammo...most other groups are around 1 1/4" using that ammo....handloads shoot an inch, but their not tailored to a 16" barrel (rolled a LOT of a batch that my 20" shoots real well).    

Their parts kit is not as good as the Armalite I tried, but it went together, and I only had to trim 2 coils off the front detent spring.  

Shipping and transfer fee, if appicable, will bust your budget...I agree you need to up it a little.  A kit gun won't look like a Knight's, but it'll shoot.  And if you're on a budget, what else could you ask for?  

An AK variant and 2000 rounds of ammunition?

I don't want an AK myself, but I wouldn't mind  running a couple of hundred rounds through one. They are interesting machines.

Pete

Hmmm, let's see.

I just bought a Colt 20" pre-ban large pin upper and bolt carrier group unfired, four mags and two butt stocks for $200.  That leaves me about $250 for a complete lower. I need a little for a brake to replace the flash hider and get a Bushmaster large hole adaptor pin.

This upper was tecnically available to anyone, but I'm the first one he asked [):)]

I can't beat 500, but I think I did pretty good, building what I call my EE(e)-AR. This is what I wanted to build;
A J&T 20" Expedition
Retail price for the kit-489.95+18 for shipping
Mega lower at local gun show-120 w/tax and background check.
Total cost-627.95

Enter the Equipment Exchange.....
Mega lower, 89 shipped, 25 FFL fee- 114 total.
Bushmaster A2 trapdoor stock- 45 shipped.
J&T 20" Expedition Upper w/b/c/ch- 360 shipped.
(This is the only non EE purchase, hence the little e.)
DPMS Lower Parts Kit(e-bay)- 55.85 shipped.
Grand total-----  574.85
Total savings using EE--- 53.10
Hours spent chasing this stuff down--- Priceless.


Kush

Looking good.. keep em coming! if $550 seems more realistic to you feel free to use that figure as an upper limit.  Please try to post deals that anyone could recreate tomorrow.

well built a ar for cheep.
stinger lower: birthday gift
lower parts and upper:$15-paid shipping for shit i traded some one i had sitting around for a few years and didnt need
buffer:$6-shiped
buffer spring:$5-sent with some other stuff i bought

total-$26

the 2nd chepest all new gun a built was
cav15 lower:$80
j&t kit:$480-shiped

total=$560

RRA complete lower 230.00 shipped and includes FFL fee.
16" A2 upper complete  390.00 shipped.
total 620.00  
Sorry but its the best I could do.

The Model 1 lightweight I just built...

$400 for the kit,
$25 for green furniture,
$100 for the stripped Eagle lower, in person

...so if I'd gotten black furniture, it's $500 plus shipping...$517 total  

That's about as close as you're gonna come to your budget, under the conditions you specified.  

let's see, heres what i did:

E/A lower $99+$26 shipping & x-fer
J&T low pts kit ~$60 shipped
ACE ARFX stock kit $129
RRA mid A4 upper, arms #40, surefire G2 all for $502 shipped

total= $816

did i win?...............DAMN IT!!

Olympic Arms cast receiver from FAC $89+ $10 s+h
Model 1 Sales CAR15 Complete Kit $400+ $18 s+h
FFL Fee to tranfer the receiver from FAC $35
State Police Background Check Fee $10
Total $562

Done two such group buy's for the guy's at work.  Assembly by me...zero!

I've had to swap out Model 1 safeties more than once though.  Bushmaster adds to the price $$$ but they work...always!

$20 for a 0% forged lower
$400 for a model 1 kit
$420 total.

I have not done this yet, but I have a mill, and I have some 0% forged lowers on the way.

BTW I just finished a 1911 for under $300, shot it today for the first time.

one more thing, Milling machine $600, tooling $500. [:)]

Here's my deal:

$128 Bushy lower (inc tax)
$453 Model 1 16" A2 w/welded brake,A2 stock, sling,gapper,USMC manual

$581, but of course, being my first build, theres:

$160 (6)USGI mags
$16 Permaslik G
$100 Kobra sight
$25 A2 scope mount
-$100-didn't like the Kobra
$200 Eotech 502
$80 Flattop upper (forget A2 mounts, go flattop for Eotech)
$40 Reciever block
$30 Telestock
$23 Fobus Surefire mount
$15 Accessory rail
$80 ARMS 40 (pending)
$15 Vertical foregrip
$10 CAR buttpad

Still need: Side sling/light mount
20" flattop Upper
Leupold Scope
M4 barrel
M44 handguards/ maybe SIR.........

You get the Idea.
Funny, I told my wife I'd build it myself to save money..........

Mega Lower $89 delivered
FFL fee    $5 Talk about a fair guy. Also sells computers and has a resatrant and bar in an old Synagogue I love this place!
M&A 20" kit $435 delivered.

Total $529

Not to get off topic in my own thread but... is the M&A worth the $15 more over the Model1?  Along the same lines are the J&T kits worth the extra $50 over Model1?

Oh... and nice builds BTW

"New" as in still in bubble wrap straight out of the box?  Or "new" as purchased from a vendor & not just some guy at the gunshow/arfcom EE/eBay/misc from your own parts bin?

CMMG is within driving distance so no shipping $$$  
Not including tax or NICS/transfer fee, etc

DPMS stripped forged lower from CMMG $105
lower parts kit $59
16" postban A3 upper $386
used M16 stock (CMMG lists them) $5
buffer, buffer tube, spring ~$35
total=$590  needs a scope & rings but bfd, I can just pull the cheap 4x32 Tasco off the 10-22.

Same idea, but using some EE/ebay deals:

same DPMS lower from CMMG $105
lower parts set $59
M16 buttstock $5
buffer, extension & spring ~$35
bolt, bolt carrier assmbly $125
CavComp for post ban compliance $20

EE
complete A1 upper with charging handle $175 [url]http://www.ar15.com/forums/topic.html?b=7&f=22&t=176417[/url]
Total=$524

If the ban goes away ditch the CavComp & save $20

Sarco kit for $350 + $30 for shipping [I want it over nite]
$110 for a stripped lower
$20 for transfer.

$510.00

I guess you'll have to have the tools already!!

Sorry, I missed the "new parts" condition of the post.

I search the net for 2 hours and the best deal I could find was from WWW.gunsnstuff.com, 16 or 20inch kit for $399 and a forged T3 Olympic arms lower for $89.
Kit      $399
Lower    $ 89
Transfer $20
Total    $508

Im on my second build, so I had all the tools,Mag's and stuff...Should be done this weekend.If you are thinking of building more than one, and who shouldnt be, I found it was cheaper to buy the kits and not parts seperatly. Price it up yourself compared to buying parts. Like the bolt and carrier.I found it cheaper the buy those parts as a complete unit instead of parts. So buy it like that and strip it.WWW.cheaperthandirt.com has spring and pin kits and some other AR stuff cheap.I have ordered a carry handle they have on clearance for $30.Its for my third build, I just need the flat top upper and another lower.

Century international lower, traded an old level 2 vest for it. Model 1 sales upper, 285.00.  Bolt and carrier 69.00 on ebay.
DPMS lower kit 48.00.
Total 402.00
Shoots great.
Gotta get another bolt carrier though, the guy on ebay ripped me and sold me a M-16 carrier so I took it out of the weapon.

A little grinding on the M16 carrier will make it legit.  Will look ugly if you don't reparkerize it but cheaper than buying another.  

This is beating a dead horse but it's only illegal if you have enough M16 parts in the rifle to allow it to fire more than one round with just one pull of the trigger.  Having less parts than that and an AR15 is legal.  Do a thread search if you want to see the copious diatribe on this subject.  I did not believe it at first, and owning an M16 and semi's made me concerned, but after researching it thoroughly, I dispelled the myth for myself.  Some shooters use the M16 B/C for the extra weight.

BTT

FAB 10 stripped lower $289
   + $35 CA/FFL fee
   + $7.50 Tax

BM Lower Reciever parts kit $50
   + $8.60 Shipping

So far...... $390.10  For Complete lower

That leaves me $109.90 for an upper.[%|]  Crap living in CA bites.

A fun and practical idea you guys have here, I've enjoyed seeing the different solutions people have come up with - I'll tell you my own under-$500 solution after the ban sunsets, but for now I'd better keep it to myself...  
I have a suggestion that might make things even more interesting:
Remove the requirements that parts be new. You could probably stay under the $500 ceiling more easily if you allowed buying surplus parts such as GI M16A1 uppers, furniture, etc. Keep it fair by requiring all parts be advertised for sale to the public in a legitimate publication such as Shotgun News, Gun List, etc., or from an established e-vendor such as Bushmaster, Fulton Armory or whatever.  
Must be sold by a company, not an individual at a fixed, advertised and therefore verifiable price. No auction stuff, since there's so much variation in price.
OTOH, now that I think about it, auctions are real transactions available to the public and are verifiable by their item number, and if you're really shopping hard on a budget perhaps eBay, Gunbroker et. al. should be allowed? Well, that last suggestion is up to y'all to decide. Just thought I'd make some suggestions to help make it more fun.
Might allow a lot more for the budget.