Thanks for your feedback! One of the main topics for the next update is re-balancing the game. The upgrade for categories after play is one of the main topics for this rebalance, as it is too op for some categories. Just as some prices for items on the shop.
Regarding this bug, do you have more info on it? The items were visible in shop but the buy but was deactivated?
I really did enjoy the game though, my main critic is that its just a simpler version of Balatro so its almost like why would I play this. I think that if you added something to make it more unique then it would distance the game from Balatro. Also add more categories like in Yahtzee (which I bet this is also based off of).