It would be awesome if you could change your weapons and clothes you get with crowns or $39 cards as you level. Not every level, but maybe every 10, there could be a way to level up your stuff.
I never understood why it couldn't be, KI seems to think it will take money out of thier pocket but in all reality it doesnt, and we did technically buy it so its ours. Hopefully one of these days KI will pull something like this.