We know the owners: they've had it from new, FSH etc.
Only concern is it has done 387k km (240k miles). Do the OM612 engines cope with that sort of mileage? Are there any major issues that should be looked for?
I have a 2003 ML270cdi Inspiration which I have also had from new, FSH and mine has done 140,000 miles (225,000 km), the only thing that has conked out so far are the parking sensors. Obviously yours has done more miles but highly recommended, everything else being equal.