I don't know why everyone includes costs yet to happen when they talk about aircraft ownership. The engine overhaul at 2000hrs is only a recommend, you can, if all is good, probably fly that for another 1000hrs. Also, how do you even know you're going to own the airplane when it comes to overhaul? Don't count your chickens until they've hatched.
Nobody would dream of including the re-spray cost on a car or have a fund for an engine overhaul 20 years down the road, or include the service costs, so why do it for an aircraft? Count the fuel, the oil, insurance and the hangarage. The rest are variable costs that you can include after the fact, not budget for.