I agree with Pooky. If he needs them gone to start renovating a building, get a few bids and take the best one and move on. If he has 6 months before he starts working on the building then you can take the time to inspect each game. I also cleaned out my building about 4 years ago. I sold working valley darts and pool tables for a couple hundred each. I threw tons of old parts in the trash. People told me I was crazy and was throwing away cash if I held out for top dollar, it could have taken me 6 to 12 months to sell everything at $1000 rent a month plus utilities. Plus you need to add in the hassle of dealing with people, PayPal, shipping, and the countless hours of evaluating and listing.
My best advice is if he himself isn't into games just sell it off and move on.

There is money in there. Unfortunately the time and work it would take to get that money would average out to $2.47 an hour. His best bet is too offer to anyone who wants the whole lot for free on the contingency they take it all by th he end of the month.
The other option would be to have a open house garage sale. Sell anything people are willing to take and hope you collect enough money to pay someone to come haul the rest away.

I just said it for the amount of time you spend it would come out to maybe $2.47 an hour. If you spent 40 hours a week for 5 weeks cleaning it up, I am sure you could get $494 out of it.

These were used for gambling. Not very popular here in MI, but would see them at the auctions in NC and Tenn. all the time.

Should change the name of thread to "how to get rid of a warehouse full of arcades and pins."