At $300-350 I'd buy one just to have something different that was fun to shoot.
Anything more than that and I would really have absolutely no use for one.
I work in a gun shop one day a week and we recently got a PMR-30 in. Holding it I'm not really that impressed by how it feels in the hand. It's going to be a giveaway gun for our upcoming move, i'm sure somebody will be really happy with a free PMR-30.