I never worry about high miles because I don't mind replacing worn parts. I have had Toyotas with over 700,000km and know of at least one with over a million. I currently have a BJ70 with 550,000km and I've been trying to catch up to a buddy with a little over 600,000km. Weird things start to wear that you wouldn't necessarily expect. Things like power steering pullies and axle splines. Other things you expect to go like window regulators etc. That 4runner is the right age to have loads of parts in the wreckers and good parts store support so you shouldn't have to rely on the dealer too much. The question is, is it worth the $2 or $3K savings over one with half the miles. You need to decide but I'd gamble it is.