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 - $700
Lightly Played - $600
Moderately Played - $500
Heavily Played - $500
Damaged - $400
Near Mint Spanish - $700
Lightly Played Spanish - $600
Moderately Played Spanish - $500
Heavily Played Spanish - $500
Damaged Spanish - $400