I think as a broad statement average mileage usage in the UK is 12-15k a year.
Anything above that is high .. 7 year old car puts you around the 105k mark.
I quite literally just brought a 55 plate motor and was looking between 40-70k, the majority were 60-90k for something tidy. still had a new alternator and ‘stat within the first month (1300 miles) but the freezing spell may have aggrevated that. Thankfully under warranty though.
As someone else said it depends what you’re gonna use it for. I wanted low mileage because it’s already a 7 year old car and I’m going to whack on 20-25k a year now with my new job
My Brother in Law just sold is 02 plate Golf 2.0 TDI at 120k coz it was getting pretty shoddy around the edges (and his uncle’s in the biz which means he could’ve had stuff done cheap too) but it was a hop’n’stopper.