The Gallade EX (34 / 108) card can be found in the Roaring Skies set.
Recently sold 5 times and based on those sales is worth around £1.86.
Currently, there are 6 open listings for this card on ebay.
This card sells in the range of £1.13 to £2.59, making it very stable.
This Rare Holo Ex card was illustrated by Eske Yoshinob.
The fact that it is a EX card makes it one of the more valuable cards.