When I checked Volvo's website earlier this year, the service indicator stated £380. And that's what my local Volvo dealer quoted me. It included their 'Volvo Assist' package which I recall was break-down cover. This was a 'minor' service, so no belts/tensioners etc.
In the end I went with an indie as I wanted them to check a couple more things (and I trust them having used them previously). I recall the service part of the work was about £230.
I reckon Volvo's own breakdown cover is worth £100, so the dealer's price isn't actually that bad, ignoring the fact you can do it all yourself with Volvo parts for 3 times less