I do tell my customers before I start a "Nearly In Box" game that the chances of getting their money back on resale are slim. This allows the customer to decide if they want their "holy Grail" restored to a high standard.
Most dealers price their games high so that buyers cannot "flip" the game for an easy profit. Classic title is Twilight Zone. If a buyer picks up a $8000 TZ and thinks it is good value at the time and then adds $500 mods, they might believe that the game has a "market value" of $8500. The moment they realize they will never get that price is the moment they realize they have been ripped off. But some buyers moving on games stick to the $8000+ pricetag. The idea is that because they were ripped off, they will simply pass on the "ripoff" to another buyer.
I don't have a problem with an $8000 TZ IF the games has been restored to a high standard. Not just the "standard" changing of non working globes and rubbers, a quick clean and replace the minimum amount of parts and spent less than 30 hours on it. Then it is a $4000-$5000 pinball.
Newbies are still being conned on eBay. They impulse buy and then when the game fails they do a search for "pinball repairs" or "pinball part" and find AP. That's when the penny drops. shame they didn't find AP first !