As a quick non-Maserati comparison, my 911 (a 997.2 coupe from 2011) has cost £2280 in maintenance over the last 12 months, and I've covered 2100 miles in that time. That's £1.08 per mile.
That is purely for repairs, so does not include costs such as fuel (estimate £650), insurance (estimate £300), MOT (£50) and tax (£360). If I add those in, it becomes £1.73 per mile.
And given I have other cars, and the Porsche is purely an extra toy, I can't really use the "I have to drive something, so these costs don't count" argument. Hence they do need to be added in to the whole ownership cost equation.
Looking at values, asking prices have not changed at all over this time, so I'm ignoring the topic of depreciation. (Man maths!)
So, £1.73 per mile.
I'd imagine this is comparable to a Maser GS, GT or QP, driven over a similar distance and time frame.
As for 2024, it's booked in for a major service in February (at £1200) and will need new front tyres soon afterwards (estimate £400). And some paintwork (I'll guess at £1000). Consequently I'm assuming next year will be very similar to this year.
What I'm not going to do now is sit down and go through all the files of all the other cars. No good could come of that!