Thats great stuff Ghost, I used to get it free from several local dentists until they were told they had to used a certified disposal agency. It's pure, very soft and you hardly have to scrape any junk off the top of your pot. I heard a quote yesterday of 40 cents a pound if you are selling it to a scrap dealer and 60 cents a pound if you are buying it. You can also see if they discard the old x-ray aprons and if you get really lucky you can tear down an old x-ray room, it's in the walls and the floor.
TJ