The Umbreon (BW93) card can be found in the Bw Black Star Promos set.
Recently sold 2 times and based on those sales is worth around £31.34.
Currently, there are 6 open listings for this card on ebay.
This card sells in the range of £30.00 to £32.68, making it very stable.
This Promo card was illustrated by The Pokémon Company Art Team.