My advice would to be ride it & check if it shifts cleanly without noise or stiffness then accelerate hard in 2nd & see if it jumps or makes a noise before buying, I would also say it will happen at some point so factor the work & the price of parts involved into your buying.
I'd expect to pay more given what the bike offers, but $2000 or so seems to be the going rate around here. That one is a bit nicer looking than most. I'd have no bad feelings about preserving it as a stock example from ye olde days of power sporte. I remember seeing a lot of FJ's in California when I was out there in 1989 for a while, usually with luggage mounted on the rear, and (if the road was at all open) usually passing you doing at least 90 mph.Chances are it's been cared for as it should. $2200 is dirt cheap. A fair early 1100/1200 non abs should be around $2500-4000.