First of all, shop your propane price, we are paying $1.5 per gallon, minimum 200 gallon delivery. $2.50 is probably Ferrell gas (also known as screw me gas...). If you own the tank, shop everyone you can, if you don't, shop anybody who will rent you a tank. Next year, fill up in summer, summer fill was $1.2 per gallon last summer.
Second, buy more propane from the cheaper place! You will not save money using space heaters unless you only heat one room. Our house currently has electric heat...it won't for long, just moved in last March, so December has been first cold month, bill is about $550... By next winter there will be a 500 or 1000 gallon propane tank next to the house, filled in summer and forget about it all winter...

