that is why you collect the cash before the pinball machine gets loaded

Not rocket science. If you were to blame for dropping or damaging it. Make good on it.

Even if you were already paid.

LTG : )™

It goes both ways. If you're buying, and you make a big gash in the wall coming up the basement steps, what then? I know it's not always feasible, but pins for sale should be in an easily accessible place for the convenience of both the buyer and seller.

From the seller's standpoint, take the cash and don't touch the pin again. Make sure buyers bring enough help. If the pin is in the living room and the buyer busts through your all-glass storm door on the way out, it's his fault, but avoid the situation by having it in the garage.

From the buyer's standpoint, I don't want to be responsible for home repairs trying to get a pin outside, and if a pin is accessible, I can get it into my truck on my own with ramps and a hand truck. That way it can't even be my friend's fault it breaks on the way up.

When all is said and done, I think it's the seller's responsibility to have a pin ready to get out of the house in the easiest way possible. Not exactly easy in a third-floor walk-up, but once it's out your front door it's over.

Always tell the buyer once it moves it is theirs. I will help troubleshoot but any issues are not my problem because right now it works. If I dropped it and it was my fault, I would compensate them or buy it back. Have yet to have it be a problem though.

I don't want a buyer damaging me, my house, themselves, etc.

Don't just be worried about damaging a pin, take a guess at the medical bills if someone gets crushed under a pin that is being moved on a flight of stairs.

I feel responsible to get the pin onto the front sidewalk/curb or driveway of my house. I am able to do this on my own with a good cart and/or a lift table. I ask buyers how they want the pin packed for shipping and to open doors for me, I keep them away from stairs and tight spaces. This is not a good time to have someone who is an inexperienced mover ram or try to brute strength things, that is where I see injuries and damage. Pins are not hard to move if you plan and have a minimum set of tools.

Once the pin is to the tailgate of the buyer's car/truck, but before loading starts I very explicitly tell them they are in charge and only give suggestions if asked. If the pin shifts in travel or the backglass falls out and breaks on route I want it to be the buyers packing choice, not mine.

I sold a jackbot years ago to liteguy, in a fozen parking lot. Longest
10 feet ever. But it was his, before we moved it.
Only game I miss.