*Beowulf:
Funny "ha-ha" or funny "strange?" Oops. I guess I just answered my own question.
The good news is that the local (Missoula, MT) Toyota dealership services Lexus also. The cost of replacing timing belt on the 4Runner is $270 total, not really that expensive.
I did some calculating and the premium I must pay in fuel to own the LX, driving as I do, is $390 per year, based on fuel price of $3.00 per gallon. Another discussion thread showed an insurance premium for LX to be $180.00 per year more than 4Runner.
I've decided it's worth $570.00 per year, or $47.50 per month to own a nice LX. Now, I must convince the present owner that my offer is a fair one.
***
The non-stock things I want are few: spare tire on swing-away rear mount; auxiliary fuel tank where spare tire used to be; as thorough skid plate protection as I can install; seat covers; some sort of cargo bed protection.
The fascination with locking differentials eludes me. To use them efficiently appears to require turning them OFF at critical times -- for example, when turning. Since rock crawling is not one of my hobbies, I suspect installing lockers is not something I'll do.
My main outdoor passions are elk hunting and fly fishing. I do not believe lockers are needed to reach my base areas. However, if I'm wrong, I can install lockers in the future. By the way, if lockers ARE needed, can I safely install on one (rear) differential, then on front differential if the rear is insufficient?