1995 shellder pokemon card value - Fossil Set 54/62 Common Psychic Rarity Pokemon Shellder and Cloyster Vintage

You can't directly purchase single cards with cash or gold

There was a thread a few months back for the Pok-Emotions game with a focus on Sleepy linked here which would likely give you a starting point, but I would imagine it is not all inclusive to every card with a sleeping Pokemon

The price tag reflects that playability

Standout options feature heavy trigger attributes, meaning that when an opponent manages to break through defenses and cause damage, the revealed card can instantly leap onto the field for free or disrupt the enemy's attacking line

The card was often used in stall-based decks

Personally, if you don't own a copy, I would buy selected singles instead and save some money