Any fitness store like academy or hess? fitness should carry similar if not the same dumbbells. I think most are probably 50cents a pound, but don't quote me on that. There are some types that you can add weight to the dumbbell, but I find just getting a few mixed between 10-35 usually works fine. Only get something higher if you're really serious. Plus a 75 pound dumbbell is a monster, if you've only lifted in pe then you probably don't want to pick one of those up.