I own a humble 6-seat twin-engine piston plane - Piper Seneca ($150/hr on fuel alone), and have been flying for more than 10 years. It's not in the jet world, but I have some appreciation of the magnitude of costs involved.
Like exotic cars, the price tag of the plane itself is just the cost of entry. I think a rule of thumb is around 5-10% a year in operating costs. The big items with jets are the A/B/C/D/E/F/G inspections which are mandatory and come into play based on usage (ie. hours) and calendar time.
The following gives you some idea of the actual costs involved:
www.sijet.com/download/13Phase_Hawker800.pdf
The 800 is 1980 era, whereas the 800XP are late 90's and up. You can pick up a an 800XP starting at around $2m. The worst item in the maintenance lists is around $60K for every 5 years, but you would also be dropping $10K-20K every year or so along the way for the other items. Plus parts. Picking up a "bargain" used jet usually means the big maintenance item(s) have been deferred and are required right away.
Then there is fuel. The 800XP burns about 250 gal/hr (although it's usually specified in weight per hour but piston pilots deal with gal/hr). At $5.50/gal, you'd be looking at about $1500 per hour. So a typical 3-hour oneway trip would be $9000 for the round trip. This is why charter starts at around $3000/hr in order for them to make any money after overheads.
And as someone has pointed out, no one owns a jet unless they fly a lot (otherwise it makes even less financial sense). So to fly the minimum 100 hrs a year - fuel cost would be $150K per year.
Hangar storage at a full service FBO for my plane is $2K / month. For a small jet which takes up more space than mine, I would estimate $3K per month or about $40K per year.
So all in all, maintenance / fuel / hangar add up to around $200K per year. Throw in say part time contract pilot + FlightSafety recurrent training, you'd be up to $300K per year excluding insurance.
My figures are in-line with Flyinglakland's - mine are a bit on the low side but as they say YMMV.
$300K per year on a $2m jet seems high at 15%, but brand new the same jet costs quite a lot more, and maintenance and parts costs are really about the same on either brand-new or used jets. So the same $300K on a $8m brand-new jet would be more "acceptable".
There is no doubt that dabbling in aviation makes exotic car ownership seem like a bargain :lol: