The reason the tires cost so much is they are made just for that car, Bugatti spec'd them from Michelin, so low production volume means a lot more cost.
So the Bugatti's upkeep costs are about on par with basic storage and upkeep for a similer cost boat. It looks like a Veyron will run you $50k a year plus anything that breaks.
Thats about what it would cost me to own and lightly use a 55 Hatteras for a year.
$10k for storage, $20k for fuel, $20k for maintenance.