One of the local pick'n'pull salvage yards lists fuel tanks at $35 pulled by the yard. They probably pull them for safety reasons and because they want to drain it first - yards generally use the gas in their equipment. I'm not sure if that price includes the fuel pump or level sender... They list those as well at $17 and $12.
I bought a tank from a different pick'n'pull 4 or 5 years ago for $40, sender and pump included, but that was entirely self-serve. Well, they gave me a bucket to drain the gas into, and a good friend who works at the yard gave me a hand by picking up the car with a loader.