I have been successful with a couple of warehouse buys. The one earlier this year, the op wanted a price but I feel it is best never to give a price but instead work your way in. Tell them you will give them a fair price but need to see the games. I think how you relate to the op means as much as the price. Make sure they know you will not bother them for repairs/etc. I always work some small talk to get to know them and it seems to have worked. Try not to intrude and work to their schedule. Be prepared to take junk also, just get a price that works out. Might have to overpay for some but keep the big picture in mind.
Best of luck