The Porygon-Z (100 / 100) card can be found in the Majestic Dawn set.
Recently sold 1 times and based on those sales is worth around £12.80.
Currently, there are 4 open listings for this card on ebay.
This card sells in the range of £12.80 to £12.80, making it very stable.
This Rare Holo Lv X card was illustrated by Ryo Ueda.