This seems like a common issue. I found that here in my area there are a small number of heat treat facilities. I found the closest one sells Parks 50 to knifemakers that ask nicely. I am told a six pack of Negro Modelo opens the bosses mind to selling a can for a reasonable price. He does buy pallets, so a single pail once in awhile wont hurt him.
Maybe in your area is some similar situation. I mean this to everyone reading this, not just godogs57!