@GeorgwSanJose Exactly! Way back in 1963 I was offered an XKE Jaguar with verry low mileage for an attractive price, way less than market.
The guy selling it was from a family who had a dealership of GM cars. The car was won in a lottery, but the new owner could not shift gears, so they traded it. The dealership had trouble getting anyone interested in buying it.
I went to a Chrysler dealerhip and got prices for all the common repairs and did the same at the Jaguar dealership. This was a real eye opener, with Jags costing 3 times as much to service plus all the extra things like “decoking the cylinder head” every 20,000 miles, adjusting the valves with the shims under the cam followers.
I don’t know of too many people who actually do all this but a friend’s young son just bought a VW Golf GTI, “real cheap” from a complete stranger. I feel sorry for the repairs he will be facing, but his dad knows that beforehand I offered any needed advice on car purchases.