I wouldn't say half the milage is a little more money.
Quick search on Autotrader
VOLKSWAGEN GOLF 2.0T GTI 5dr Hatchback£7,250
2006 (56 reg), HatchbackTrade seller, distance: 116 miles
52,500 miles
Manual
2.0L
Petrol
9
1
52,500 miles, 2006 '56' VW Golf GTI 2.0T 5 Dr Hatchback, 1 owner, 6 Speed manual, Met black, Low mileage - ONLY 52K, Full VW service history, recent service/cambelt! …
So they are out there! this is a trader btw, so he'll have a grand into it straight away, people need to look harder

100k car makes no sense to me...
Thom