I think cost of ownership also depends on the owner, and whether you're one of those "while i'm in there anyway, might as well replace XYZ..."
I just bought a 1 owner LX470 with 224K miles in November. I have LEXUS dealer records from mile 1,000 through 223,000 at regular intervals.
On the COLDEST day of this winter so far in New England (-11*F), the plastic top of radiator developed a hairline crack-- that was $170ish for a new Denso unit.
And while replacing the radiator, I decided to use my airgun to blow out the AC condenser. I started to blow out some of the fins in the middle that had become brittle and soft with age. So while I had it all apart anyway, I ordered a new Denso A/C condenser. That was another $144.
And while I was in there.... might as well get a new Thermostat (per the last timing belt, the current thermostat was definitely still good with only 50k miles on it), but I changed it anyway. That was $20 bucks. And then a new upper and lower radiator hose to change out the originals, another $50. And the T's in the back, another $40 bucks.
And for peace of mind, the fuel filter. Another $30 bucks.
So I think cost of ownership at this mileage totally depends on the type of owner you plan to be as much as anything else. And, obviously, how much of the work you can do yourself.