The Venusaur (13 / 53) card can be found in the Wizards Black Star Promos set.
Recently sold 11 times and based on those sales is worth around £53.95.
Currently, there are 10 open listings for this card on ebay.
This card sells in the range of £34.23 to £73.67, making it quite volatile.
This Promo card was illustrated by Ken Sugimori.