I get a lot more from servicing my bikes than simply money.. Firstly I know it's been done properly, by someone who cares, no wondering if they actually have cleaned the air filter etc.
Secondly it gives me a chance to see first hand what's wearing, and what isn't, do I really need new brake pads or are they just trying to flog me some brake pads? I'll check them again in 500 miles and see how they're doing.. If they're wear much more I'll swap them, only a 10 minute job because I have them off at every service to clean, I could do it with my eyes shut..
You become much closer to your bike if you service it yourself, it's part of the ownership experience for me. And, spending a day servicing your bike works out cheaper than actually riding it.. Win/win..