Hi Andrew,
Just a few comments which may add some perspective.
The design was basically unchanged between 2008 and 2013. Apart from the spacing of the letters on the bootlid and larger logo on the front, there's nothing to show that it's a 2013 model. The R-design was just a trim package and not a lot different to the T5 - floor mats and seat logo ?
Mechanically they're capable of big kms too, so there's little advantage (to someone who knows about them) between one with 30,000km and one with 100,000km. (In fact low km cars often have greater issues - short trips to the shops are much worse for wear than interstate high speed runs).
It is 8 years old, even if you say it's a 2013. The timing belt is due for replacement in 1 or 2 years time just because of age, which is a big expense at a garage. It's an "old car", but not really collectable. The "low kms, one lady owner driven to Church on Sundays" really doesn't have any value in the real car ownership thing.
The metallic trim inside the V50 is very easily marked and scratched. The value of the car will be largely determined by whether the leather has been regularly conditioned, the handbrake lever still has the stupid rear cover and the door lock buttons still have the grommets - and whether AM still works on the radio...all annoying "wear features" but useful to judge whether the car has been valued or not. As Essbos says you really need detail photos to judge the condition.
Summary: You should be able to get $10,000 - $12,000 for the car, but if I was shopping and found a 2008 version with 100,000km for half the money, I'd buy that one instead because it's basically the same car. (In fact that's what I talked a friend into doing - except the 2008 model had AWD...)
(In other words, you may be better off advertising on Carsales to non-Volvo people than trying to get a good offer on a Volvo enthusiast site)
I suspect that's why you haven't had much feedback.
Good luck, Nathan