"most of that platinum could later be recovered from the reactor wall, so it still wouldn't be very expensive. " And recovering comes for free? Every step cos

"most of that platinum could later be recovered from the reactor wall, so it still wouldn't be very expensive. " And recovering comes for free? Every step costs energy (or money). There is no working design yet. It is waay too early to make any predictions about how scaling could reduce costs. Scaling can even increase costs, if it depletes limited resources like tritium.