I'd say 4-500 bucks is about right if you really don't care what brand is going into your rifle.
To me the appeal of assembling yourself is 1) You get to assemble it yourself. 2) You can build what you want straight away rather than buying a rifle for 1000 bucks and then replacing 500 bucks worth or parts. Potential cost savings isn't really the main factor to me.
I'm currently putting together my first AR I shopped sales, and bought parts from the EE. When I'm done I'll probably be into it for 1300 bucks but to buy the gun I would have wanted otherwise was going to be $1600-$1800 depending on who's posting it on the EE. The lower half of mine might not be perfect, but the upper half doesn't get much better than what I'll be running.
