I like cheap content.  When I was young and foolish, I bought CDs and never used most of the pics on them.  Now, I only buy pic sets.
I've bought a lot of stuff from 
NottinOnYou.  They have a variety of different niches.
This latest two sets, including the big one, I got from 
PixMasters.  They've been around forever.  I think I remembered when they opened and were very small.  Now, they're a whole lot bigger.
I look wistfully at the really high quality content, but at this point, don't feel like investing that much.