$10m out of the original 450 m purchase price isn't bad, about 2%.
If we compare to a luxurious passenger SUV like a Lexus LX600h, that's like 120k, it's about 1,000 for annual maintenance.
This is oil changes, oil filters, engine air filter, cabin air filters, wipers, inspection, differential, transfercase. (transmission ATF changes are once every 30k). And that's for a car that sees 10,000-12,000 miles annually in driving. A car getting like 30-50k miles a year would see a lot more wear items. Tires, Brakes, more fluid changes, ATF, water pumps, bearings, seats, radiator, condenser, etc.
A380s are turned around and do about 2 trips a day for every day unless it's in maintenance, the route is discontinued, some international incident occurs, the plane is sold and transitioned to a new owner, or the airline goes bankrupt.