Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.) At the beginning of your upkeep, put a rust counter on each artifact target opponent controls. Then destroy each artifact with converted mana cost less than or equal to the number of rust counters on it. Artifacts destroyed this way can't be regenerated. When Corrosion leaves the battlefield, remove all rust counters from all permanents.
Near Mint - $400
Lightly Played - $400
Moderately Played - $300
Heavily Played - $300
Damaged - $200
Near Mint Spanish - $400
Lightly Played Spanish - $400
Moderately Played Spanish - $300
Heavily Played Spanish - $300
Damaged Spanish - $200