The Blastoise ex (104 / 112) card can be found in the Firered and Leafgreen set.
Recently sold 6 times and based on those sales is worth around £69.23.
Currently, there are 4 open listings for this card on ebay.
This card sells in the range of £43.80 to £94.66, making it highly 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.