I just had my 1995 850 turbo sedan's pnp switch changed at the local volvo dealer for a grand total of $238, parts and labor. To me, that sounded very reasonable and included no work of my own.

One of the things my dealer mentioned is that there is a 20% discount on labor for all volvo cars fixed at volvo dealers, if the cars are more than 10 years old.

Of course, you have to make sure that it is the pnp switch and not anything else.