The Mew (19 / 165) card can be found in the Expedition Base Set set.
Recently sold 3 times and based on those sales is worth around £83.77.
Currently, there are 2 open listings for this card on ebay.
This card sells in the range of £65.00 to £102.54, making it quite volatile.
This Rare Holo card was illustrated by Hajime Kusajima.