Feedback needed on ShopUI

This is a new ShopUI I made for my game dysfunctional defence:

Please give me any feedback. I want to improve this UI and make it the best it can be for release.

That looks pretty great! What else is in the shop?

Well the current item in the shop is just a template so all the towers I place in the game will be displayed there ig

Looks nice. Maybe in the sub-frames you could add a darker gray? Idk if that would look good or not. Great job keep it up!