I just thought of a couple of other ideas that might be useful. Use Freecycle. There are Freecycles in almost every area of the country. All you need to do is post a request or look through the offers. I am involved with a little group that makes crocheted and knitted things for charity and they were looking for a way to get inexpensive yarn. I mentioned Freecycle and they got tons of it right away.
Also visit estate sales and garage sales at the end of the day. They would rather take $1 than throw the item into the trash.