The Gardevoir EX (155 / 160) card can be found in the Primal Clash set.
Recently sold 3 times and based on those sales is worth around £6.94.
Currently, there are 15 open listings for this card on ebay.
This card sells in the range of £3.71 to £10.17, making it stable.
This Rare Ultra card was illustrated by Ryo Ueda.
The fact that it is a EX card makes it one of the more valuable cards.