I don't know how many times people who are not really familiar with Volvos have made a hash of things or cost customers lots of extra money, but the problem is quite large.
Every vehicle has it's quirks and you want someone working on yours who is familiar with them.
For example, many FWD and AWD Volvos suffer from failed ABS control modules. A tech reading out error codes would be told by the computer that a wheel sensor or other component is bad. However, the problem is usually that an internal trace in the controller has gone bad and it is the trace which connects to said sensor. Thus the error codes are simply wrong. To make matters worse, this failure mode is intermittent so that it is quite possible to replace the wheel sensor $$$$, clear the codes and have the ABS light go off .... only to come on again a few days later. Volvo techs know this and aren't going to piss away your money replacing perfectly good sensors.
I could go on and one with such stories, but the point is simple. There are also issues of using correct fluids for the various systems, knowing which aftermarket parts are acceptable and which are junk, etc. etc. If you aren't going to learn to do it yourself either find a Volvo dealer you trust or an independent specialist who works on Volvos all the time. These shops are out there and are worth looking for.
Cheers, John