PSA will probably have this one on sale at some point in the next couple weeks for around $500. Good quality, complete with excellent BCG, and a $150 handguard to boot.
Figure $150 for a stripped lower, $150 for a PSA/Magpul lower build kit...you've got a quality gun with a nice rail for $800. All that's left is sights/optics and ammo.
I've been keeping an eye on the PSA 300blk page myself lately.