Proof
Bronze V --> IV =6$
Bronze IV --> III =6$
Bronze III --> II = 6$
Bronze II --> I = 6$
Bronze I --> Silver V = 10$
Silver V --> IV = 10$
Silver IV --> III = 10$
Silver III --> II = 10$
Silver II --> I = 10$
Silver I --> Gold V = 15$
Gold V ---> IV = 15$
Gold IV ---> III =...