The Gardevoir ex (96 / 100) card can be found in the Sandstorm set.
Recently sold 3 times and based on those sales is worth around £17.95.
Currently, there are 11 open listings for this card on ebay.
This card sells in the range of £5.76 to £30.14, making it quite volatile.
This Rare Holo Ex card was illustrated by Hikaru Koike.
The fact that it is a EX card makes it one of the more valuable cards.