The Gengar ex (108 / 112) card can be found in the Firered and Leafgreen set.
Recently sold 12 times and based on those sales is worth around £108.89.
Currently, there are 6 open listings for this card on ebay.
This card sells in the range of £26.71 to £191.07, making it highly volatile.
This Rare Holo Ex card was illustrated by Mitsuhiro Arita.
The fact that it is a EX card makes it one of the more valuable cards.