my father has owned a 2000 4Runner SR5 for the last 6 years or so, got it when it had around 50K miles on it. Since then he has kept up with regular maintenance, and the only additional issue he has had is with his rotors (needed replacing twice in 2 years). Other than that this vehicle has been rock solid, taking abuse from Maine winters, and a 16 year old male learning to drive on it. The truck currently has 230K miles on it, and still looks and runs like it was new. No rust, no body damage, no mechanical issues.
Saying this, most 4Runners with 200K miles on them probably were not maintained as well as my fathers, so it is a guessing game. I would much, much rather buy a 4Runner with 200K miles than a Chevy Blazer with 75K miles.
Good Luck