The Dark Magneton (39 / 109) card can be found in the Team Rocket Returns set.
Recently sold 5 times and based on those sales is worth around £5.00.
Currently, there are 4 open listings for this card on ebay.
This card sells in the range of £0.01 to £10.45, making it quite stable.
This Uncommon card was illustrated by Emi Miwa.