Rule of thumb I go by- if you play it at a local Namco arcade anyway, enjoy it, and it says for sale on the site (it never does in person anymore), go for it, go right up to the employee on duty and say you saw it on the site for sale. Dial up a couple of friends, pull up a truck, and drag that sucker out of there.
Otherwise? Mixed bag. Can't say I suggest it, especially not for a drive. Maybe for the rarest and grailiest of grails but it's just too risky. The prices are all pretty flat rate, and although you get a better deal on older games, condition is NOT a factor in pricing. Back in the 90s I surfed for a Ms. Pac Man, flat rate around 780 bucks, and out of all of them only one had a monitor that was even barely visible, and it's sideart looked like it had been through a blender.
If you're in the area anyway, drop by, drop some tokens in, and give it a shot. But I would never drive out long distances after agreeing to a deal sight unseen, unless the game is worth their asking price in parts. I highly suggest driving out first, having friends and a truck on backup, and THEN play the game/talk to the employee as if you were a local. Never call up ahead of time and say "I want to buy game XYZ". I've seen everything from the peppermintiest of mint cabs for sale to cabs that feel like you're looking through a glass of milk to even see them with half of the buttons ripped off or without a functioning microswitch. Approach with caution.
-MF