I just added about 50-100 hotel room key cards to my store on Delcampe. Latest additions are listed first with generic hotel cards before casino. That makes over 2,400 different key cards currently listed!
Here's a direct link to the hotel key card listings. If you want to only see casino cards, add "casino" in the search box and click on the magnifying glass. That will bring the list down to about 1,700+ casino hotel key cards.