So far the only precuts I've bought have been Hoffman Bali packs, which I LOVE (no duplicates, 40 different coordinating batik strips per pack), and I've also picked up some 5" charms and 2-1/2 strips from Connecting Threads when they were on clearance - I practically stole those.
I buy the Hoffman Bali packs from Beverlys.com; they're almost always on sale for $29.99. Not exactly cheap, but for a nice sampling of gorgeous & good quality batiks it's something I spoil myself with every now and then. In the store (Beverly's is local to me) they're $39.99, so it's worth buying them online.