it depends on how well maintained the car was and how many pre owners it had.
if the car was mainly used for long distance trips on the highway it is better than if it was used by mommy for shopping and taking the children to school (well ok, in finland this could be long distance
).
the m60/m62 V8 ist a very reliable machine. we have some members in this "forum" with well running cars and over 500k km.
you also can be quite sure that the speedo was not manipulated. some cars with real 300k are sold with manipulated 180k. a lot of people fall for this old trick.
if you would post pictures of the car we could tell you more about what we think of its condition.
greetings to finland