I think Matt is right on about finding the pistons for that price. Thats about $100 lower than I've seen them anywhere other than Ebay. As for the Machine work, that also seems really really cheap to me. I had just a head done a while back and paid $200 to reseat the valves, clean it up, and install new seals. Can't imagine that decking a block, honing/boring, hot tanking, cleaning, etc is cheaper than a head. I also can't imagine that there are too many machinists out there that have a torque plate for an SR20DET either.