Where can I sell my Facebook page?

You cannot sell your Fan Pages.

However, you can reach agreements with other people in your niche. Think of it as a very large mailing list, you can sell ads from people to "send" to your Fans. They could buy publications, explosions, group meetings or anything else you can think of, for a certain period of time (or in progress) for the price you decide.

But I say again, YOU CANNOT sell your Fan Page correctly.