I got lucky and had the winning bid on a lot of miscellaneous stock at an auction. It turned out to be over three tons of aluminum, brass, stainless, carbon steel, tool steel and plastic shapes and plate. As it turned out, I was the only one bidding on it for what it was instead of for it's scrap value and ended up paying just over $1000 for it. I sold all of the G10 and polycarbonate for what I paid for the lot and kept the rest. If I need anything special that I don't have on hand (rare) I usually get it from McMaster Carr. They are a bit pricey, but their selection and rocket fast shipping make it worthwhile.
Tom