If you are serious, you need to get the codes off the VIN. there is literature out there for that purpose, likely online now. Don't take somebody's word for it that is is "special".
So it's a 2 door body - with a Mustang motor.....under $10,000....and then I'm not really sure - demand is the deal - how many really want this wagon ? Maybe under $7500 if it's nice and you can drive it.....let him list it somewhere - most likely he has with no takers....
That's like comparing apples and oranges , Cougars and Mustangs , Camaros and Firebirds..... Also , rarity doesn't mean valuable, you still need desirable
Is this the car? Nada shows high retail around 26k with the original 260cid. Not sure where you are seeing base Falcon wagons selling for 15k, buy I've been seeing a lot not sell for 7k asking price on eBay.
Remember, 'rare' doesn't always mean 'desirable' or 'valuable'. And sad to say, but the Mercury versions usually sell for less than the cheaper Ford versions. Trim parts can be very difficult to find.
damn....I'm buying those little Falcon wagons that are sitting around here locally and on flats....must forget my mom's 64 Falcon wagon we camped out in a bunch of years......and sell-sell-sell.........