Could it be that the X150 is finally appreciating in value because there are so few quality Grand Touring competitors in this price range?!
Either way, I will hang on to my now almost 10-year-old XKR ... Nothing I have driven has been remotely comparable, or as reliable, so I feel like I beat the casino!.

 

I would not buy the 4.2. After owning the 5.0 (2010) for 2 months now, even with 380bhp it does not feel as 'quick' as say an F type. I know its a GT and the F type is a roadster but the end of day, its a sports car and power is power. Get a 2010+ instead you wont regret it.

EDIT: I got my 2010 XK with 53k miles on the clock and full service history for USD 8k.... only issue was that the car was resprayed, with no accident damage though just to refresh the paintjob.

 

I am have been shopping around for a 2011-14 XK/XKR and that seems like a lot of money for that old of a Jag...I would say 12-15 thousand would be right......I would spend more time looking around unless you for what ever reason “have” to have that year and model......

 

I have recently seen 07-09 XKR variants with 100k more miles than the OP mentioned go for low teens. 12-15k just isn’t realistic for a 15000 mile car. Even if it were just a base XK not an R.

i think the car the OP mentions, if all mint, is worth low to mid 20s.

 

I've been saying this for years. These aren't massed produced Toyota s with "market" pricing, they're extremely low production cars, mostly because there wasn't enough demand to begin with. This can be good or bad for pre-owned resale...either they sell for a premium for their scarcity and condition, or, they sit and sell for a fraction of their retail.