It exists in several finishes (Normal, 1st edition). Each one has its own price; the average above is for the regular version.
Artwork by Ken Sugimori. Some collectors chase every card by the same artist: how to start (in Spanish).
Attacks
Psychic
ESP
Flip 3 coins. If exactly 1 is heads, draw a card. If exactly 2 are heads, this attack does 20 damage. If all 3 are heads, choose 1 of the Defending Pokémon's attacks. Misty's Psyduck copies that attack except for its Energy costs. (No matter what type the Defending Pokémon is, Misty's Psyduck's type is still Water.)