Hi and welcome from North Carolina! Your quilt is beautiful! Wonderful job! You've come to the right place for all kinds of information. A very inexpensive way to built a stash is to visit thrift shops, if there are any in your area. You can buy large clothing with lots of useable fabric for very low prices. You'll have to do some deconstruction, but it would be a whole lot less expensive than $25 per yard!!
Keep quilting and enjoy!!