Thanks again to all.
The carfax was not a concern, it is not true miles unknown, sometimes clerical errors happen.
Never got to ask the seller about it as he called to say another person wanted the rig today for $13k cash, no inspection, and was offering to let me match it. I talked to my wife and drove to see it one more time and he was coming back from a test drive, called me saying “the guy is at $13,500 now” at which point I told him this wasn’t an auction and I’m out.
Buyer was a broker who will probably put new tires and flip it for 20k. There’s nothing on the market in this area for less.
So, decision made, I’m out a carfax but learned a lot. Thanks again.