The Swampert ex (98 / 100) card can be found in the Crystal Guardians set.
Recently sold 4 times and based on those sales is worth around £22.97.
Currently, there are 9 open listings for this card on ebay.
This card sells in the range of £13.90 to £32.04, making it quite stable.
This Rare Holo Ex card was illustrated by Ryo Ueda.
The fact that it is a EX card makes it one of the more valuable cards.