Late to the party but, could the translator/editor have made it clearer? I believe the author meant the exterior(?) of the helmet costing USD$40, and selling it for USD$50, since Jiang Chen had "contracted the specifications of the 'Phantom' helmet out to workshops in Coro Island" The editor really needs to work on their clarification, even if the author does not state it in my opinion. Just shows their lacklustre attempt to make the story good. Many grammtical errors here and there, and the horrendous country names.