yard sales and estate sales along with craigslist are really good places to buy fabric inexpensively. on craigslist in my area some have been selling fabric at $1-$2 a yard. at an estate sale i recently bought 3-4 yard pieces for $2.00 each.
also for online purchases try www.5bucksayard.com. the fabrics are popular manufacturers (marcus brother, moda, etc) season closeout fabrics and there are a lot for sale at $2.99 - $3.99 per yard. most everything on this site sells for $6.00 or less per yard.
i have some scraps and what i call practice fabric (a bit thin) that i can send you for $5.25 postage. pm me if you are interested. i will stuff what i can in a flat rate legal envelope. if you want i probably could stuff a flat rate box size full for $11.00. i have plenty of tshirt knit fabric that you can make tshirt quilts with. let me know.
mary