For a single 1st stage and two 2nd stages, I think $75 would be about the maximum for the kits. That's still an outrageous price considering what the kits include; a few o-rings and maybe bushings, a seat, and a filter element.
well what ever the cost for the parts are, my indisputable point is this, if you buy from an authorized dealer you DON'T pay for parts as long as you have your products serviced according to the ScubaPro Warranty, if you don't buy from an authorized retailer then and don't keep the service up you do. You may save $300 up front but cost for parts will FAR Exceed the money you save up front.