In NZ, the 100,000km mark is significant - five years old and 100,000+ would be considered 'high mileage'. No-one says kilometrage, except me
Anything bought at over 200,000km, whatever the age, is 'high mileage'. Toyota Utes and vans are frequently over 300,000 in the cheap listings. I bought a six-year-old 156 that had clocked up 237,000km in Singapore - surely something of a record for a country that only allows the car to be driven on alternate days. After rebuilding just about everything, the car served me well and the current owner is about to roll over 300,000km.
Most people are conditioned to expect a cambelt service at every 100,000km, though Alfa owners expect it rather sooner than that as we look for five-yearly changes.
My Gtv is 15 years old and has just rolled over 85,000km (52,827 miles) so I think that would be considered "low mileage". But not so low as to stop you wanting to use the car, which was the case with an X1/9 I had once, 16 years old and 40,000km.
In Melbourne I rode in a taxi that was three months old and already over 40,000... and in Canberra I rode in a 10-year-old taxi (about to be retired) that had 2.3 million kilometres on the clock (the driver reckoned only two engines had been required), which kinda puts it all in perspective, doesn't it?