These engines seem to be quite strong, if serviced properly.
If not serviced properly, timing chains can be an issue, which is an involved job, expensive if you can't do it yourself.
This engine needs regular oil changes, using the correct oil. If there's no proof of this, walk away.
It will have a diesel particulate filter (DPF). This needs frequent regeneration, which happens at constant speeds, with the engine fully hot. A low mileage suggests short journeys, which can clog the DPF, and prevent regeneration. A professional clean or replacement is expensive. Diesels with DPF do not like local running around.