As a quilter I always buy fabrics when they are on sale. But, as you know some cheaper fabrics do bleed in the prewash. I always pre-wash my fabrics to remove the resin/sizing. I throw in a Shout Color Catcher and wait to see the bleed. If it bleeds you can still save the fabric with Retayne. A teaspoon per yard in warm water does the trick. I re-wash the fabrics again with a Color Catcher after treatment and no more bleed. Amazon sells this at a good price. Worth it to save the fabric you bought.
I bought a lot of red cotton yardage from a bargain bin and it bled. But just one wash with Retayne and it is now usable and I can trust no more bleeding in the future.