It’d be really cool to have an alliance shop. In other games they worked like this:
Alliance performs tasks in events together or help each other in other ways to earn points, even donating resources. Alliance points buy items to stock the shop with, usually controlled by the leader co leaders. Members earn personal points from participating in the tasks and can ask for the shop to be stocked with the item. Alliance points are used to stock the shop and member points are used to buy the items they wish.
I’m thinking it can be stocked with items like banners, potions, attack items, resources, etc.
This could be a really good addition to the game and a nice added reason to being in an alliance as a whole.