Lots of good deals on Aero uppers, both M4 and M5. Not a huge selection, but good deals on what they do have.
If you don't mind the Aero Gen 1 M5 Hand guards they've got great prices, 12in FDE Mlok w/ barrel nut for $105.
Complete M5 uppers Black $115, FDE $130.
Stripped M4 upper Black $50, FDE $60.
Anderson AR15 LPKs are also $35