so in the quest to upgrade the gear in my bag, I sold my gerber/fiskar sliding pocket saw to a friend for her pack, and im wanting to go to a buck style saw that I can hopefully fit inside of my pack just to keep things on the outside to a minimum. the pack that im running is a kelty redwing 50.

right now the main contender that ive been close to purchasing is the 15" sven saw . it folds up compactly and I could probably slip it into a piece of PVC tube with end caps and put it inside of the pack. reason being for the pvc tube is that it protects the saw and protects the pack, plus having a piece of pvc with one sealed encap can always be utilized somewhere. so far I see the sven as the best bang for the buck as far as size and weight and strength. the only caveat I have is that the price of the replacement/spare blades is damn near half the cost of a new assembly.

the price im at right now is roughly $30 since this is an occasional use item. ive looked at the bahco Laplander and all those folding style saws and im steering away from them as I can be rough with items and fear I would bend or break the blade since its only supported on one end. I looked at the bob dustrede (sp? ) pack saw but to me its too big for inside my pack and outside of my price range.

has anyone on here come up with a homemade/diy saw that is easy to create with hand tools and takes off the shelf blades for around the same price ?

Short answer...  NO.

Best folding saw IMO is the bacho Laplander.  If I need something packable its that.  If I need a bow saw I just bring a regular bow saw.  They cost less then $15.  I really like the idea of a packable bow/ buck saw but the cost for me outweighs the utility and function.

Maybe someday I will pull the trigger, but in all honestly it would only get used to its true potential about one week per year, and that would be during my week long hunting trip in the Rockies.  I always find with gear, that stuff looks neat, and I might think I need it, but do I really?  Will I use it to its full potential?

I have seen people make buck saws by hand (utilizing a purchased blade). They tend to run more than your budget as there is a lot of work that goes into making them (often mortise and tenon jointed). That said I've carried the Sven saw for many a mile. I have always carried the larger (21"?) version. I had an acquaintance once let me use his smaller version and I did not like it at all. It was too small of a cut and too shallow inside the frame. The A frame style (I guess that I can call it that) limits the usable area in the frame anyway (vs the H of a buck type of saw), why restrict that any more by going to the 15" version. YMMV.
 As to your concerns around needing an additional container: don't worry about it. The Sven saw fits into the hadel in such a way that it is really zero concern.

If you're up for it, you could try to build something like the Adventuresworn Bucksaw.

Never looked into the Sven saw myself, but it's $36 on Amazon and replacement blades are $13. Other brand blades for misc bow saws seem to be $9-11, so Sven's $13 isn't unreasonable IMO. It sounds like you want the Sven, so just go for it. Also, think about leather or nylon "caps" connected by cord on the ends of the stored Sven rather than a PVC tube if you'd like to save some weight and space and still protect your pack.

Two things:

Don't discount the Laplander, it's a solid little saw and I have that and the Gerber....the Laplander is it's equal or better.

Second, look at the Sven saw....the handles could be easily made out of conduit and put together with bolts, washers and wingnuts, don't you think?

Get a silky saw.

Bacho Laplander for light duty stuff, and a 15-21" Sven Saw for more serious stuff.

Get a Silky Big Boy.

Trust me, they are a little pricey, but they cut like a damn chainsaw. It makes the bahco saws look like childrens toys.

I take one every time now, simply can't beat them. You can zip through a 12" log in very little time, and unlike a buck saw you won't bottom out on the cross piece.

Holy expensive blades! $28+s/h for a 7" blade, no thanks.

They are certainly worth it. I was on the fence about it too, but I have yet to find a saw that cuts as well and stays sharp as long as the one I bought.

Pretty happy with my Bob Dustrude; it cuts very, very well and packs fine. I like it much more than any of the fold open blade saws that I have used. As you mentioned that is $20 more than you want to spend.

The occasional times that mine gets used have convinced me the extra $20 was worth it.

They used to make a compact bucksaw, company was called Trailblazer or something similar. I know they are discontinued, but if you are handy one can be made pretty easily, but not for cheap. I've got one in a box somewhere with my go gear. I'll have to see if I can dig it out for pictures.

This is what I carry... Never once let me down and doesn't break the bank.

Sven saw

I suggest the Sven 21"

If you would like to save weight- http://www.qiwiz.net/saws.html

I picked up the texsport shape-shift takedown bucksaw, sounds like what you are looking for.
http://m.academy.com/shop/pdp/texsport-shape-shift-folding-saw/pid-1026311?deviceType=true

If I didn't already have the saw part of my pack covered, I would be all over this.  Very interesting.