Last week I had the 48,000km service performed on our 2007 Impreza SE for $344.00.
We have 3 Subaru's and we avoid the dealership unless it is for warranty work (which, touch wood has never been necessary so far).
The shop I use actually does all the overflow work for the local Subaru dealership.
I do not think it's fair for me to advertise the shop so if anyone wants more info you can send me a pm.