Wow four boxes is a pretty rare find, I think. I believe this ammo was discontinued around 1990 or there abouts. I would imagine that someone would want to pick it up for the correctly headstamped brass.
Around 1992 I paid $35 each for two boxes and last year I bought a partial box from a member here but I can't remember how much I paid. This round is shot not only by Contender shooters, but the occasional lever gun and Martini Cadet rifle. If the price is reasonable, I think you should grab them.
BTW this is the caliber that introduced me to Contenders and later, reloading.
Curtis