Quoted from asay:
The machines he sells are just as good as new. Completely shopped out with LEDs and perfectly restored playfield and cabinet art. When you consider ~$200 for LEDs, flipper rebuild parts, and a thing else a machine would need, plus 15+ Hours of labor between the shop job and art, plus the overhead of running a full time repair shop and retail business, plus the warranty that's included....a $1000-$2000 markup from collector prices isn't unthinkable. If he bought and sold machines for the same price, he wouldn't have much of a business, would he?
Retail prices are always going to be higher. Most of us here like to search for deals and put in the work and knowledge to shop and repair a machine....but that isn't everyone. There's people who are willing to pay a premium for machines that they know will work and look beautiful from a business that has a great reputation.
tl;dr retail prices > collector prices for a number of good reasons