I have a friend who is thinking about selling me his AR (.223) due to the fact that he doesn't get around to using it. He's going to get back to me with a price. Here's the build:

Colt heavy barrel upper with aluminum tube and full floating barrel and scope rail
Bushmaster lower
Unknown make ACOG included (reasonable quality, not top end but no where near junk)
1 pinned mag.

I'm crossing my fingers that he'll let it go pretty cheap, but what would something like it be worth, ballpark price? If it's good enough than I'll be buying it regardless, and if I don't use it I'll resell.