A lot of people on e-bay are selling them. It might be worth a look at the completed listings to see what they actually are selling for and if it would be worthwhile. I bought a batch of charms a few years ago, but they never seem big enough to do anything with.
I like strip piecing, then cutting, so starting out with smaller pieces actually takes longer, I find.
I also pre-wash everything I buy, and do not know if I would trust pre-cuts not to shrink or run.