Looks like the Steem Monsters card game has finally sold out of all alpha cards. We can only look forward to only beta cards going forward unless you want to go to the marketplace to purchase more cards individually. Also you can visit their you can still get alpha cards from their kickstarter campaign. See link below:
https://www.kickstarter.com/projects/526764488/steem-monsters-a-digital-role-playing-trading-card