So I've hopefully done all my research and gathered all my correct parts from multiple makers, I'm ready to seek a gum smith to assemble my first 300 Blackout rifle length. I haven't contacted a smith yet. What is typical for assembly costs by the smith?  Are there any pointed questions/ facts to give him before he begins?  What is expected in the final product?

Parts assembly isn't really that hard. There are many quality youtube vids showing assembly of the upper, lower and other components.

When you assemble it yourself, you'll understand and learn the mechanics of the gun.

There are some specialized tools you'll need, but you only have to buy them once. Once your totally engulfed with the BRD, you'll use them over  and over and  over and over again.

If you're still not sure, I'm sure that are some ARFcom members in your area that will be happy to help you out. I know I've infected several local ARFcommers with the BRD.

Thx Nick. I think I know enough to be dangerous now.  My BCG and charging handle will arrive in 3 days and I can tinker with it over the long holiday.   Here's hoping it goes well.
Greg

Edit parts list
Barrel Alpha Shooting Sports 16" 1:8 twist
Upper. Alpha Shooting Sports
BCG. Griffin Melonite coated
Charging handle Gunfighter medium
Lower CMMG complete assembly
Flash suppressor. Proprietary design by a guy on 300BLK talk
Optics will be either a Trijicon 1x4 or a vortex red dot.

i wouldnt consider paying someone to build it for you. there are so many videos on youtube or info on here that you can buid it yourself. it is very easy. i built my first lower using the guide on here.  now i have built 3 lowers and 1 upper. it is pretty simple. watch a few of the videos on youtube and you will gain the confidence to do it yourself.

you can get a torque wrench and a vise cheap at harbor freight and a clam shell upper holder and an armorer wrench on ebay pretty cheap. if you get stuck on some part of the build you can make a thread and someone will help you with your questions.

You should build it yourself, you'll be glad you did. I didn't know a thing about the AR-15 before I got started so I did my research and watched a lot of youtube videos and folks on here are very helpful and I found it to be very easy to do. My first AR is a .300 BLK, I'm working on my 2nd one which will be a 5.56. I see you're in Alabama, if you live near Huntsville you can call me and I'll be glad to help you with assembly tools if you want.

Thx Drkhorse. We love in Winston Co and do make it to Huntsville ever so often. I will prob do it myself just because like you and others said, I'm doing this for the experience and fun of making it myself. Prob the only concern is the headspace. Since I already have a vice block, the only thing I'm missing is the go or no go spacer.
Greg

+1. This. If you can build with Legos you can build an AR.  Very easy to work on and put together.

Your headspace should already be good if you bought from a reputable barrel maker, but if it makes you feel better I would just have your gunsmith check it for you. Gauges cost around 30 bux each and my gunsmith charges me 50 bux an hour so if there is a problem he can go ahead and fix it.