Spells you cast have affinity for artifact creatures that weren't originally artifact creatures. (They cost 1 less to cast for each artifact creature you control that wasn't originally an artifact creature.)
1UU: Target permanent becomes an artifact in addition to its other types.
Near Mint - £12.20
Lightly Played - £10.40
Moderately Played - £8.50
Heavily Played - £6.10
Damaged - £3.70
Near Mint Non English - £12.20
Lightly Played Non English - £10.40
Moderately Played Non English - £8.50
Heavily Played Non English - £6.10
Damaged Non English - £3.70