Quoted from LTG:Just tell them you wouldn't put a price on another persons game. Let them know if they come up with a price to let you know. And walk.
LTG : )™
Lloyd presents a great response.
Another option is to provide an actual offer. Before you contact the seller, do your research and figure out what you are willing to pay for the machine based on the shipping cost.
Then submit an offer that is lower, say 20-30% lower. If the seller is serious, then they will start negotiations. If they are not serious, or are "easily offended" by an offer, then you will learn that quick enough that this game is not meant for you.
Good luck with your future purchases!
Marcus