They don’t have just one standard service, the work schedule varies dependent on mileage or elapsed time. Also the price of a service will depend on whether you have the work carried out by a franchised dealer, Volvo independent or independent. Here’s a link to the Volvo Owners Club discussion on servicing costs. Prepare to dig deep.
Forum for the P3-platform 60-series models
www.volvoforums.org.uk
Don’t know what engine you are considering but I had a XC70 with the 2.4 five cylinder diesel and four wheel drive. Towed very well.