yarn of all types..cheap or free is best...homeless

It's that time of the year again when I am looking for free or cheap yarn of any size color or length. I crochet hats for the homeless every year, this year I made 450, and then an additional 80 for an Elementary school. I really do crochet these hats, and I take care of my husband who is on disability, so I cannot afford it myself. If you can help, or would like to, it would be greatly appreciated. Thanks and God Bless. See picture below, this is just a few.