TL;DR: No, it's not worth $12k. As mentioned above, probably a car lot on a fishing expedition for a fool and his money.
I haven't followed the used market lately, but at $6-$8k it might be worth considering if it's in extremely good condition with recent in-depth services and a long, documented service history, but even then I'd question the decision unless you are absolutely in love with having a 1st gen 4runner.
The 3VZE is far from perfect, but it's also not nearly the ticking time-bomb that the internet community would have you believe. I've had two; the first was in a 94 pickup and had 190k on it when I broke it being an idiot. The second was in an '88 4runner and had 345k on it when it sucked in a foreign object somehow and destroyed a piston and chewed up a head. I tore it down to the block, rebuilt it, and kept on driving it two more years before I was again and idiot and fell for the siren-song of Cummins turbo-diesel goodness. Take reasonably good care of them and the 3VZE is not as problematic as it's reputation would indicate.
That being said, they are anemic and uttery "meh" from a performance and economy standpoint. Although I wouldn't say no to the right truck on account of it having a 3VZE, it would have to be the right truck at the right price. This 4runner is not that truck, even with the 22RE.
Also consider that these 1st gen 4runners are now around 30 years old. Scads of them were made worldwide, and most chassis and drivetrain parts are shared with the same-era pickups, so hard parts won't be an issue, but the little bits and pieces are getting to be a pain in the neck to find. Things like trim, turn signals, grille, etc... are few and far between unless you live in a region where these older Toyotas were pretty common. In LA, probably less of an issue than it is for me here in "jap crap, buy domestic" country, but do bear it in mind. Pieces and parts will eventually break, and if you want to replace them it will be painful, either in terms of time spent finding them, or cost; possibly both.
I LOVED my '88 4runner and would happily own another if they could be found in decent condition for reasonable prices still. I wish there were an LMC truck or Man-a-Fre catalog equivalent for 80s era non-LC Toyotas, because they are some of the best vehicles ever made and I'd love to have another without having to worry about finding parts in a timely fashion.
