The Mewtwo & Mew GX (242 / 236) card can be found in the Unified Minds set.
Recently sold 9 times and based on those sales is worth around £83.50.
Currently, there are 11 open listings for this card on ebay.
This card sells in the range of £59.62 to £107.38, making it highly volatile.
This Rare Rainbow card was illustrated by 5ban Graphics.
The fact that it is a GX card makes it one of the more valuable cards.