You can get the 50 deck rate for even a single deck (and there are often coupon codes) at https://www.printerstudio.com/unique-ideas/blank-playing-car... or https://www.artscow.com/photo-gifts/playingcards

Also, if you're trying to give this away, they both allow you to share a link to your design so other people can buy the cards direct.

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edit: the sites may seem cheezy, but they're probably responsible for 95% of prototype card decks that professional designers print.

For other excellent non-Chinese, Buy America options, there are https://www.printplaygames.com/product-category/prototypes/c... , https://www.thegamecrafter.com/make/pricing#Cards and https://www.drivethrucards.com/joincards.php