It wouldn't surprise me if the state of CA has a surcharge of some sort on these hazardous materials. Or it could just be charging what the market will bear. In the Dallas area various shops charge from 9.50 to about 17.00 for glow fuel with 10% nitro. The 9.50 fuel is about 20 miles away, shop in a warehouse district, and the 17.00 stuff is less than 10 miles away at a shop in a retail district in an affluent area. With property price differences and other overhead the two shops probably net about the same amount on a sale.