The Vileplume ex (100 / 101) card can be found in the Hidden Legends set.
Recently sold 4 times and based on those sales is worth around £33.48.
Currently, there are 6 open listings for this card on ebay.
This card sells in the range of £16.38 to £50.58, making it quite volatile.
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.