I am lucky, I came across a member of the casting forum and he has several 55 gal drums filled with them. He gave me my last 5 gal bucket full of them and I have yet to process them but they are due soon. He told me that I could have what I could use of them from his drums and not to go buy from any one else.
But I may be moving from the area and at that point I am not sure what I will do. Probably hit the recyclers.