I wasn't saying you need to change to propane or natty gas, I was saying I can't relate to anything other than those things. And like honeybuns says, you can prebuy more than the 255 gallons and they will come top it off until you use up your prebought oil.
However, I bet 3 lbs of bacon that either the oil company, your city, your state, or uncle sugardaddy sam have a program for people that can't throw down $900 at one time. I'm 99.37% sure there is some form of payment plan or something of the like. Research it yo.