That is a good price on the 33 gallon tank. Question is, will you be installing it yourself or how much will it cost to install? I have installed a gas tank on a 1970 Road Runner and it is not the most fun process as you inevitably breathe gas fumes and have to deal with the time and frustrations of such an install. Personally, I love my 33 gallon tank because I go to the gas station less often however I probably would not go through the effort and cost of installing it if I had the 26 gallon one (unless my total cost was only ~$200, tank plus install, to put in the 33 gallon tank!)