"...cards you get in the shop cost money..." EA ?
before this day, I had just copied the code for getting cards from battle rewards to the shop. You could get a single card and it would close the shop. On this day, I wrote a new script for shop cards to make it so you can get more than one, and they take away money. Hope this helps!
Edit: Spent the whole afternoon trying to figure out what you meant by EA, and it just hit me that you were referring to Electronic Arts making a joke. Well played sir, I got whooshed.