personally I get mine wherever I can find it... places like Hobby lobby, and Fields... if you not looking for much they'll have ends of the roll marked down to sell, and pieces that were cut off because they may have a small stain or spots in an area... though if you can find a quilting place they also have cute fabric... though you'll pay more for even small pieces because small pieces are what they use in quilting and thus are not extra to them... though I've also found that places like the salvation army, gospel mission and other places that are like that sometimes have areas just for un-used cloth that people have donated... in fact the little bunny outfit that I made my doll came from some fur cloth that I found a rather good size piece of at the salvation army...
plus if you can find any old sheets with cut patterns that may just have a hole in it here or there, you can always scrap them out to make into something completely different

refurbishing is great and always better then just tossing something that could still be used, even if it's not for it's intended purpose