im not saying im for or against this conversion. but ill give you my point of view. I work in the engineering/manufacturing industry and to fabricate a hinge is not that difficult nor expensive. the piston is a little more. the molds for the steel (or plastic) are very expansive. in excess of 10,000. once they pay for the molds. which would be about 6 or 7 of these kits they really are making a very large profit. considering the materials cost just dollars and even pennies in some cases. i havnt seen these kits so i cant be judgemental but from what you said was included. just a hinge and a piston. it is a tad over priced