It's at Tatooine Traders, the gift shop at the exit of Star Tours in MGM. I don't recall the exact price, but I remember being shocked. Maybe it was around $30 or $40 or somewhere in that neighborhood.
My DH & DS had this done last May. It was in a shop that has some Star Wars memorabilia (almost like a little museum). I seem to think it was somewhere near the BackLot tour, but I can't remember. Very cute picture though!!!