Check similar games on www.PinballPrices.com Of the 700 game titles and 1700 sales databased, I don't have this machine but the Boston guide would be the next best option. It's trite to say, but it's worth what someone will pay for it, no more than that. If it's sentimental too your Dad, pay him what you can. If it's just in the way and he wants to get rid of it, it's not worth much to him.