If it is a very well trusted private seller I would go that route.

It doesn't matter as long as you can play and see the machine you are interested in buying..got burned recently on a buy from a private seller with good ratings....

So far, I've always bought privately. I can do my own repairs, so I'm not to worried about warranties. Everything I have is 10+ years old, with the exception of one game I picked up this weekend.

For people who don't want to do repairs, going through a dealer might be better way for them to facilitate that. Service is baked into the price somewhat.

It really depends on what you're looking for.

The real question is, do you know how to solder? If so, buy private.

I have bought 12 games... 11 of them were purchased through private sellers. 1 was purchased from a dealer, but it was his personal machine. That 1 machine purchase was the only time I ever feel like I was screwed in a deal. I don't know for sure they did it on purpose so will spare names/their business, but it sure looks like they knew they were screwing me.

I would not buy a pre-owned machine from a dealer unless the price is reasonably close to what I could get from a private seller and I really wanted the machine. I bought my first pin from a dealer and regret paying the price I paid. (I don't regret getting the game.) With the exception of my one NIB, all my games came from private sellers at outstanding prices.

The best people to buy from are other collectors who take care of their pins and price fairly.

Non-collectors who own 1 pin are generally cluless on maintenance and their pins are filthy basketcases. Not recommended unless the price is real low.

I do not buy resale pins from dealers. That's equivalent to flushing $1k-$2k down the toilet.

I would definitely buy from a private seller then. Dealers cost far more, you want to learn how to fix them yourself, and if there are any pin techs in your area...you are covered each way.

Private sellers, I don't like paying more and paying tax.

Not all dealers have the same quality when shopping a game. I have seen many privately shopped pinballs that were way nicer than some dealer pins. And it doesn't matter how big or fancy the dealers showroom is. That doesn't necessarily reflect how good he or his service guys are.

Also, not all dealers warrantees are useful. I have heard of dealers who sell a game but then won't come out to service it or just put you off time and time again.

Unless you are a total newbie who needs delivery, set up, and after the sale service, I would say just evaluate price and condition no matter who is selling the pin. Dealers will almost always charge significantly more than private sellers. They have to pay their overhead and employees.

If you are new enough that you might not know what to look for on a pin, you can get dazzled by all of the bright lights and sounds.
Try to take a more experienced collector with you to point out little details you might miss like faded cabinets, cracked plastics or ramps, damaged battery holders, burned up connectors, playfield wear, dirt under plastics, etc. These can significantly affect game value and can help separate a truly shopped game from one that just got a quick once over.

I have always done private sellers, but to be fair I only have one newer pin at this time, Houdini. I bought a little more than a year old for significantly less than NIB, with a ton of extras, and of course no tax. I can think of a few cases where this strategy might not/doesn't work (Tron LE, Rick & Morty maybe). For the most part, though, I saved enough to get another pin on my wishlist. So far, out of thirty plus transactions with private sellers, no real problems.

If you like nice stuff private collectors with a solid reputation are your best bet.

Numerous dealers like to throw around "shopped with LEDs" and charge a premium for some new rubbers and fugly colored GI bulbs I'd end up replacing. There's exceptions to the rule of course... I've def. picked up some nice deals from out of state dealers. Got Pinball in Florida comes to mind, great shipping rates and solid deals on newer Sterns customers trade in.

It doesn't take much effort to clean up a 100% functional game and add some LEDs if it's a nice stock game with incandescents, so the shopped vs. un-shopped part has never bothered me.