Hum, it does seem too cheap doesn't it, and if something seems too good to be true, the it usually is....main dealer too and low mileage, I have the money in the bank, hum, too many cars too little time.
Just beware with Carrs, they are (in my opinion and experience) a bit hooky!
If they say its been freshly serviced, don't take their word for it. Check the oil is clean and get down on your hands an knees and look through the passenger side of the lower front bumper, you should see the new filter up the snorkel, if new, it should really stand out.