Unless you get off of the turnpike, you will pay 10-15 cents more a gallon at a turnpike station.. I paid $2.47 at my local station.
Thant being said, if you get off at Exit 3- Bellmawr, there are two stations about two blocks from the turnpike exit. You can Buy your gas and get right back on. Today that would cost you $2.45, but gas prices change DAILY in NJ