... is to list it on there then. Start it at a price without any reserve, then let people bid on it. Take lots of pictures and post them there. Mind you there are other factors that might affect the price, such as the most recent holidays, so people may not be willing to spend as much, general condition of the item, condition of boxes, etc. As Wilm said, generally speaking people may not want a signed model, unless it's mounted on a base and the signature is on the base or anywhere else except the model. Typically you'll also have to provide proof that the signature is authentic, otherwise it's just some signed model which nobody will care about.