The Pikachu (115 / 114) card can be found in the Black and White set.
Recently sold 3 times and based on those sales is worth around £13.36.
Currently, there are 38 open listings for this card on ebay.
This card sells in the range of £6.79 to £19.93, making it quite stable.
This Rare Secret card was illustrated by Kouki Saitou.