The Wailord EX (147 / 160) card can be found in the Primal Clash set.
Recently sold 9 times and based on those sales is worth around £3.97.
Currently, there are 3 open listings for this card on ebay.
This card sells in the range of £1.28 to £6.66, making it stable.
This Rare Ultra card was illustrated by Ryo Ueda.
The fact that it is a EX card makes it one of the more valuable cards.