The places I have used to have things sand blasted just use regular sand, one of them literally by the dump truck load.
Outside, a good respirator, and heavy clothes is what I have used when I do it myself. But I would not want to sand blast for a living...
About the $50 and a case of beer, you would be lucky or have really good friends to have a frame done for that little. I think $200 is a deal for sand blasting a frame. Try it once yourself and you will quickly see how much fun it is.
Grigg
