COMC is great for buying low-end stuff in bulk, in my opinion. I'll go there and look for lower end PC stuff, and if I can find a handful of what I need, I'll make a purchase. Bought like 40+ cards there twice in the last month.
Collecting Autographs on 2014 Topps Pro Debut: 163/220=74%
Collecting Bradley Roby
Collecting Steve Garvey