Having everything you'd ever need neatly in the Main Hall is too convenient. Make it so you'd have to visit the Black Market to buy things like Codebreaker, a set of lockpicks and a bloodhound tracker.
Let the seller jack up the prices overtime (I'm thinking in thousands) unless you do favors for them. That way you'd have to be more mindful of how you spend those resources and the Main Hall would stop being a Walmart for burglars.