Graves RC in Orlando FL is about $15.00 a gallon as well. Here in Sebastian it's $25 a gallon or more. One is 25 miles away, the cheaper place is 75 miles away. Best to find a glow buddy to split gas and you buy it by the case, and we do.
Another way to go is getting a 55 gallon drum of methanol race fuel, add your own castor oil. You really don't need the nitro to run a 2 stroke glow engine (FAI for example, I've used it for years, cuts down on bearing failure too) unless of course you have 4 stroke engines. I've seen clubs do this routinely.