Some exclusive or complementary ideas regarding a store's linked storage:
Automatically close a store that has no storage room for the things it's buying (adding storage space to status requirements);
Decrease the quantity of an item being bought in a store, matching the storage capacity for that item. For example don't let the store advertise it's buying 1000 sand if it only has room for 234;
Advertise the carried and general items storage available for the store at it's tooltip;
Some exclusive or complementary ideas regarding a store's linked storage: