The Raichu & Alolan Raichu GX (221 / 236) card can be found in the Unified Minds set.
Recently sold 6 times and based on those sales is worth around £45.00.
Currently, there is 1 open listing for this card on ebay.
This card sells in the range of £31.15 to £58.85, making it quite volatile.
This Rare Ultra card was illustrated by tetsuya koizumi.
The fact that it is a GX card makes it one of the more valuable cards.