I don't even spend that much per year on fuel, much less maintenance. Bought at 38,000km, six years ago. Now sitting at 126,000km. Just under 15,000km per year. Ballpark 16L / 100km, that's 150 * 16 = 2400L of fuel per year. At $1.80 CAD / L, that's $4320 in fuel per year.
Oil change every ~8 months, ~$120 CAD.
Front pads + rotors, every ~2-3 years: $500 CAD.
Alignment every couple years: $170 CAD.
New battery every 3-4 years: $120 CAD.
Add a set of tires every 4-7 years.
Water pump was replaced under warranty. Fuel pump recall done at Lexus' cost. Radiator looks fine. No issues what so ever.
I paid out of pocket to replace a squeaky belt some ~3-4 years ago; a few hundred bucks. Outside of the dealer-caused, dealer-fixed, dealer-paid-for AHC fiasco, that was the only unexpected repair in my ownership. I can't predict what it'll be like at 500,000km, but in the 6 years I've owned it, the LX has been perfectly reliable with very minimal maintenance costs.