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 - £23.20
Lightly Played - £19.70
Moderately Played - £16.30
Heavily Played - £11.60
Damaged - £7.00
Near Mint Non English - £23.20
Lightly Played Non English - £19.70
Moderately Played Non English - £16.30
Heavily Played Non English - £11.60
Damaged Non English - £7.00