Been looking at getting a 2007/2008 Supercharged (ironically due to ULEZ) and there are a lot with mileages in the 130-140k range. Could just be a coincidence as it's ballpark average mileage but I'm suspicious...

Is there a huge service due around this time and that's why people get rid? Supercharger belt/pulleys seem to be due a replacement around this time but that's all I can find so far.

mine has this now and touch wood moat stuff started falling off around 110k so hoping she's ok (struts, alternator , o2/maf sensors, supercharge oil, all 8 coils etc) I guess you could find one that's hung on in there ut I think its just average mileage Current stable:
2006 BMW M6
2007 4.2 V8 S/C FF
Gone:
2002 4.4 V8 FF

Best advice would be to buy on condition and service history.

Mine is on 136k and I've just replaced everything on it!

Buy privately, preferably from an enthusiast or forum member and spend a decent amount of time looking through the service history and the receipts for work done.

Buying from a dealer these days is a waste of time as any receipts the previous owner gives them will be thrown away due to GDPR.

David. 2002 4.6 Vogue SE - Alveston Red with Lightstone Leather
2007 Range Rover Supercharged in Java Black with Ivory Leather
2012 Range Rover 5.0 SC Autobiography in Indus Silver with Jet/Ivory Interior
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior

Bought mine (2007 4.2 sc) with 138k miles about 10 months ago, it’s on 150k plus now. Alternator went on it, front air strut went 1st week I had it so changed both front ones. Aircon condenser was rotten that got changed. Have done some suspension parts but will do the rest ( handles like a whale on AT’s😂). I have it serviced every 5k miles.

Gearbox was done by previous owner but I plan on getting a mega flush done. Rear wiper never worked since my ownership, got a replacement and get the tame grease monkey to change it.

Computer says average 12.5 mpg which is probably about what it is.

To sum up my ownership experience, it’s the 1st time in my adult driving life that I have bought a car and have stayed off auto trader for 10 months. If I was to replace it, it may be with a new defender but even then I don’t really see what you gain with them over an L322, mine is more capable offroad then I will ever be and the L322 has larger load and access area from looking at defenders.
The seats are supremely comfortable and the driving position has amazing visibility when coming out of roads with hedges or cars parked too close. The only quality of life addition I want is apple car play and then it’s the complete package.

They are vehicles with lots of engineering solutions to defy physics, those solutions need maintenance. Keep on top of it and you will have a fighting chance. Also when buying (if private) I check the seller more than the car. Does this person look like they took the car to LR when it needed washer fluid? That’s your guy hahaha 😝
On the other hand if it has had painted wheels, dodgy tint/wrap and ditch finder tyres I run!