I have two F12's, and did in fact pay $1500 for one of them, freshly rebuilt with new paint and gaskets. A more typical price for this stove in good used condition is $900... if you can find one local. In my case, the rebuild plus saving a day on driving to any of the others I found (mostly in New England) was worth the extra $600.
There are not many known defects to this stove. The air control lever does tend to stick in the closed position (better than open
), but Jotul added an access plate to the later stoves just below the doors in the firebox to access and lubricate this mechanisum. You can cut the plenum and add your own access plate, if your stove has this issue. The cat chamber is somewhat fragile, which is only an issue when servicing the cat. Otherwise, it's completely hidden behind / protected by cast iron. The cat chamber costs $250, and the other two pieces of refractory (lower and cover) are about $65 each. Cat's cost about $160 - $200, depending on which you buy. Just make sure that any cat you buy does NOT have an expanding gasket around it, as this will destory the cat chamber (this rules out the Condar ceramic cat, although their Steel Cat is just fine in this regard, and is what I have in one of my stoves now).
Inspect it well for cracks. Don't fret too much about failing cement, unless you think it lead to the stove leaking and overfiring. There are lift-out side panels, so the fire never touches the outer stove body (think box in a box). The side panels, and the lift-out rear burn panel covering the cat, are all replaceable, and are the components designed to take most of the abuse. I had a hairline crack in the rear panel on one of my stoves, which I replaced because I'm anal about stuff like that, although it did not affect stove operation at all.
The top lifts off easily with the removal of two bolts two screws for the top door lift mechanism. It's gasketed, not cemented. Replacement glass can be obtained thru Jotul, or any stove shop that sells custom cut ceramic glass. Like any cast iron stove, it does require a yearly going over, pulling out any loose cement you find at the seams, and re-caulking those seams with stove cement. It's really not a difficult job, but it must be done.
Like others, I'm real curious why it was used so few times. Clearly they must have had some problem with it.
edit: I forgot to add that, if you want the performance of a big cat stove in an attractive cast iron package, this stove is one of the very few options you can find. Sadly, there is simply no directly comparable stove on the market today, and believe me when I say I looked. Hopefully the BK Ashford 30 will change that, albeit in a slightly smaller package.