The Porygon (71 / 108) card can be found in the Evolutions set.
Recently sold 1 times and based on those sales is worth around £0.48.
Currently, there are 6 open listings for this card on ebay.
This card sells in the range of £0.48 to £0.48, making it very stable.
This Uncommon card was illustrated by Tomoaki Imakuni.