I had a hard time buying the cards at first. I think this was due to the fact that creativity is hard to put a value on. I ended up buying two packs (I gave one as a gift), and I can honestly say that I have used them hundreds of times. I think the price of the pack actually forces you to get your money's worth out of it. Being creative in your life is one of the best investments you can make.
Just curious: can you recount a time when a card has broken you out of an idea deadlock in a real life situation?
I can definitely see how this could work (I've used writing prompts in the past and they've helped). Just wondered if there were examples outside of the writing world.
But you can get a feel for the idea online, eg https://www.joshharrison.net/oblique-strategies/
This site used to have some really funky color combinations that were inspiring all on their won, but unfortunately it's a little bland now.