Mustang II's are pretty rare in general as far as I'm concerned. But don't buy it because it's rare, the II's value doesn't necessarilly increase due to it's rarity. As far as T-Tops go, their not really rare that I know of. I havent noticed a lacking in them. But don't expect it to up in value any time soon. They are just not as valuable or desirable as they should be. But if you like the car, buy it and enjoy it. They definetly are not seen around very ofton and contrary to all those bullheaded mustang owners, alot of people like them. I get compliments on mine ALL the time. Good luck. =)