I tell people that they better expect to have to deal with issues, as something WILL go wrong between now and the near future with the game. It’s sold as is, and even if something doesn’t work when you get it home, that’s how these things can be.
When asked, I will take a $100 non-refundable deposit to hold, no more, no less. I confirm (make sure I state it in an email) that you can have two weeks, or whatever we agree to come get the machine and pay in full, otherwise the deposit is mine for holding up the sale, and my time. If they needed a few more days, I will most certainly agree, but by only expending the original conditions. Some people will say they will give me half now, and they are fore sure getting it, but I stick to this $100 method, if it’s a situation where the game can’t be picked up that day.
I think this is fair, and allows everyone to confirm each’s level of commitment to each other. Any issues after, I’ll try to assist by phone or email, or by providing some documentation etc, but I’m not fixing it, not even for payment. I’m at the age where time is more important than money.