2006 LC100 here, daily driving mine, at 207K all original miles, but I work from home about 75% of the time, the rest of the time, I am driving all over for work, with the days that I drive putting on 200+ miles... sometimes, I drive 1,200 miles a week.
I bought it used with 90K miles on it 7 years ago, and I paid it off 5 years ago. The typical mileage I get is 16mpg avg. between all highway, and going up and down mountains around Colorado. Also, I run a K&N air filter and it does make a solid 1+ mpg difference when driving vs. a Wix professional air filter.
I get paid by the mile when driving for work, at the IRS rate, but even at that, with the minimal maintenance cost and long tire life, even with the gas it uses, I make a profit driving it.
I can't imagine driving anything else at this point. I have a neighbor with a twin turbo 3.5L Ford F150 and I rode with him to go buy a lawnmower, and I noticed his fuel mileage was 14mpg at 1/2 tank, so I don't believe that everything else out there is much better in the real world.
I hope to keep everything well maintained and hopefully my son will get to drive this beast in 10 years or so, when I have 400K miles on it....