Sounds interesting, I would consider following features for owning a business:
-gives you passive income (like bank interest system)
-gives you active income depending on how much people buy stuff from your shop (market - lottery tickets, coffee, etc. club - drinks, and so on)
-takes away your money for each cashier and safe robbery (like item replacement inside the house) either in 1:2 ratio or whatever
Of course there should be ability to sell, transfer the business to somebody else, perhaps an upgrade system (like house one) where cashier and safe robbery takes 1.1% longer or something