I bought a real dirty DK JR cocktail for 150 cleaned it up added a 10 dollar button, played the heck out of it and then sold it for 200 to a fellow collector.
If it works, is complete and the monitor does not need any work even with the cracked glass I would pay 100 to 250 if I wanted one to fix up.
Condition is key and the amount of work you are willing to do. If I was looking for a real nice example that I did not have to do anything to except bring into the game room and go.... I'd probally pay up to 4 or 5 bills for a real nice one.
As I have gotten older I am more willing to pay a little more for a nice cosmetically looking game that requires no patch work.