It's possible you got a prior owner that didn't take care of it at the beginning of its life... because the Toyota 4Runner was one of the better Toyota built vehicles.
Also, here in Southern California, we have a glut of them for sale... so many used car shoppers are focused in on the Honda CR-V and its bigger brother, the Pilot... or the Toyota RAV4... they have lost sight of the Toyota 4Runner.
The best examples are from 1996-2002, which are bullet proof with any type of maintenance on them. When they came out, new prices ranged from $19,000 for a base model up to the top of the line Limited Edition model that could top out at $35,000... but in the used car market, there is not much of a price difference from the base to the Limited Edition. Prices here in Southern California seem to range from about 3000.00 to about 5000.00 for a top of the line Limited Edition model. But because they were so reliable, many people ran the mileage up on them, and many are on their 3rd or 4th owner, and for some maintenance wasn't in its life plan. So if you get one of these bargain basement SUVs, you will have to go over it with a fine toothed comb, because they had a lot of options and most were expensive to repair. And in this era where mechanics are charging 80.00 to a 100.00 dollars per hour, and parts cost are through the roof... you can't make an error on a 4Runner.
Also, unlike the new car based SUVs... like the CR-V and RAV4... they are on a truck suspension, which is not for the smooth set. But if you grew up with trucks, especially early Toyota mini trucks, then you will fit right in with a 4Runner, because basically it's a Toyota Tacoma pick up truck that has extra seats and an enclosed cabin, and it's built for hauling stuff. It's a heavy duty vehicle in a small package.
I would rather avoid an old vehicle like this (now 24 years old) and not pay mechanics 100 per hour to bring it up. I would rather buy one that burns more fuel that is newer for a better buy.
It wasn't too much to pay 12 years ago. This was the fully loaded luxury version. Even with 250K miles, it was still worth $6K. If the maintenance costs had been a little lower, depreciation of $1800 over 7 1/2 years is pretty good I'd say.