Ok, looks like I'm in the minority here! I will try to explain. From what I've seen, there is no economic justification for buying a 15 yr old HDJ81. They are expensive to buy, service is difficult to arrange, and shops, if you are having service done, have to be found that can deal with these trucks. So, you are right, I did the same thing, and that decision does not necessarily make total sense. What was my justification? I have always loved Landcruisers. I would have bought one years ago if not for the rust problem.
I could have picked up a US imported truck for about 12000 less than the diesel I got, and that's BEFORE the nearly 10K extra I've put into it, which now stands at about 30K. I do believe the quality of the vehicle I'm driving now FAR surpasses anything on the domestic market. So...based on finances only, it's not sufficient to justify my decision. But to own a unique, capable and fun vehicle has benefits you can't justify based on price alone. I had a Lexus GS300before this truck and I much prefer the truck, so I do have some ideas on refinement - although driving to a Lexus dealership and driving around in their service loaners, while they paid for gas, is a far different experience than looking after a 15 year old HDJ81.
For "quantum leap" I was thinking of putting a 1HDT into a US 80, or even a cummins, or something like that. Another friend of mine has an HJ61, and it is a VERY different vehicle from an 80. From what I've read on here, after this buyer gets his 14K 60 into shape, I bet the cost of doing what I am thinking of would not be that different from what I'm proposing.
Where did the money go? Well, by the time you've replaced the big end bearings, had all the fluids changed, tested the turbo, cleaned up all the minor problems, serviced the brakes, etc etc etc, you are a long way into cost. Also put a high end stereo in the truck, because the Japanese one that was in it was useless. 10 speakers in the truck and I had heard better sound coming from a clock radio. I also found out that the prior owner had removed BOTH swaybars, which I replaced with US spec bars. Another 600 bucks. Anyhow, I don't know if that makes any sense, but it's an attempt to explain my thoughts. Which apparently are in the vast minority here, so I concede I'm probably just plain wrong. I'm also somewhat anal about vehicles, and want everything to work, properly. I'm a non conformist thinker as well, hence my decision to convert to duracool. You should hear some of the shops here. "It's illegal", "it's dangerous" etc etc. Most people like to go with the heard. I know most of you reading this don't either, but even here I'm a non herder. Now on to the tough dog shocks. Even though this forum tends towards OME and Bilstein. LOL....