I have a copy of Super Mario Bros. Deluxe (GBC) that I am thinking of selling. I would be selling the game, box, and manual; all in excellent condition. Price checks on ebay weren't helpful. I found loose copies recently sold ranging from $0.99 to $19.99. There weren't too many boxed copies sold recently: one was $12.99, another was $24.99 (both had additional inserts beyond manual).
Not sure what's a good price. Any suggestions?