The Cacturne ex (91 / 106) card can be found in the Emerald set.
Recently sold 7 times and based on those sales is worth around £31.78.
Currently, there is 1 open listing for this card on ebay.
This card sells in the range of £10.99 to £52.57, 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.