Have I got a great find for you ladies: There is a place called Jenny's Fabrics - they are in Fountain Valley, which is close to Costa Mesa - here's their website for contact and location info:
http://jennysfabricsdiscountstore.com
What I love about this store is that they have flat folds at the back, oftentimes some of the same fabrics they have on bolts, but the flat folds were like $5/yard in 2011, the last time I was there, and the bolted fabrics were about twice that amount.
If you are able to go downtown Los Angeles, in the rag district, you can find lots of places there as well - I highly recommend that field trip!
Happy Hunting!