Selling old barn wood?

I'm looking for some references about what would be a fair price for selling an old barn for salvage. The barn is very old. It was there when my grandparents bought the farm as newlyweds,though it is most likely much older than that. The beams cross the entire thing, they are cut from single trees and some of the longer ones are probably close to forty or fifty feet long. They do not have nails, they have the old pegs holding them together. The siding of the barn is newer, and not in good shape. There might be some water damage to some of the beams. The barn is located in southern PA.