Yep ! agreed one must look at duration as well as mileage, city car engine which often catch in traffic jam may have higher wear & tear then the odometer record, engine is running even ur car might not move a lot.

Mileage or time period which ever come first, I remember one of my friends car timing belt snap in the middle of highway drive, the whole engine jam, almost get into nasty accident, the repair cost him many folds if the timing belt & water pump price.

Be warned.