Having owned a second hand 550 for about 2 years (which I use often and don't exactly idle around), I don't see on what would you spend avg 10k a year, unless you're racking up reserves for the replacement car a few years down, or a complete refurbishment in 4 years.
I can also inform that I do my maintenance at the local Ferrari dealer on top of it, and I go there for anything that goes wrong. Ok so it's not a 360, but still, it can't be that different.
Boxer would know for sure, he has two of them.
But it must surely cost more than a Z06 to service.
... racing, it's life. Anything that happens before or after is just waiting... (Steve McQueen / Le Mans)