Currently there is no store of any sort at Blackhearth. I think it would make sense to have a very basic one that sells necessities such as oil, empty potion vials, arrows, bedrolls, etc.. As it stands Order PCs need to go to the Exiled Camp, which granted isn't very far. But I think we're the only DM faction on the PW that has to enter a dangerous area in order to get these things. That short trip can be very hair-raising for some PCs, especially at lower levels. I should think a keep would have these kinds of supplies on hand.
The same applies for Fellhammer, not asking, just saying. :D