Depends on what kind of detail and micro-management you want your players to deliver. IMC, the party got a big house (and some are still complaining it isn't an Imperator's palace...) and we just set up the staff by rule of thumb... making sure that the party could leave when neccessary without the whole organization falling to pieces.
- Double-guards 24/7 meant at least 6, better 8 guards plus one guard commander were needed.
- An experienced housekeeper/steward was bought, which in turn selected the rest of the staff, all slaves (the campaign is set in the south).
- As the DM I decreed that the party income from a deal with a merchant covered expenses for the house and staff, living expences for the party, and 100+1d100 gp cash per week.
That way my players don't have to micro-manage the house/estate if they don't want to, they can run it in an abstract way, only interfering when they desire (like for hiring a new guard, commissioning artwork, or training the staff).
I on the other hand, had not to come up with numbers and costs - I could just decree that the costs were covered by this and that income. If it was an estate, I'd rule that the estate mostly paid for itself, needing or netting a certain, variable, maybe random sum of money per week, month or year. No need to fret about income/expenses that way.
