My first service was $150...since then I have changed my oil twice but I need to have the valves checked, I'd just assume do it myself, I need to read up again on how to do it. I remember mine ran alot better after they did it the first time.
It's a piece of cake and actually if you want to just guess and readjust them over and over until you get it, you can skip the crows feet and the special tools. Once the locking nut is loose, they turn pretty easy. Must make sure you have a torque wrench however.