The Hitmonchan (51 / 90) card can be found in the Hs Undaunted set.
Recently sold 1 times and based on those sales is worth around £1.26.
Currently, there are 4 open listings for this card on ebay.
This card sells in the range of £1.26 to £1.26, making it very stable.
This Common card was illustrated by Kouki Saitou.