When you play Magneton from your hand to evolve 1 of your Pokémon, you may move any number of basic Energy cards attached to your other Pokémon to Magneton.
Attacks
40Electric Blast
You may discard all Lightning Energy cards attached to Magneton when you use this attack. If you do, put damage counters equal to the amount of Energy cards removed in this way on any number of your opponent's Benched Pokémon in the way you like. (For example, if you discard 3 Lightning Energy cards, you can put 1 damage counter on 1 of your opponent's Benched Pokémon and 2 on another.)
How much is Magneton #19/144 worth?
Magneton #19/144 is a Rare card from Skyridge (2003) — today it trades at roughly $46.70 ungraded. Across the 2 printings we track, copies run anywhere from $35.00 to $519.18 depending on the version you're holding.
Grading changes the math on this one: a PSA 10 is valued around $412.22, roughly 8.8x the raw price, while a PSA 9 sits near $104.38. 142 copies have been graded to date, and 48% of them came back a 10 — worth knowing before you pay grading fees.
These figures come from nightly market-data syncs verified against completed sales. Use the chart above to see the trend before you buy or sell.