Although the consensus from the layman is that the engine is "bulletproof", in reality, most of them will give 350K-400K before some serious work is required. This presumes that they were well cared for with proper oil changes throughout their lives.

There are many components within the engine that require some expensive service at that mileage level and, generally, it's not worth the effort due to the wear on the bottom end.

I would not purchase such a vehicle and begin to spend significant repair money on it.