Whenever another nontoken artifact you control enters, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
$17.00 $10.20
$5.99 $3.59
$5.00 $3.00
$11.99 $7.19
$96.00 $48.00
$68.00 $34.00
$5.00 $3.00
$10.00 $5.00