That sounds about right to me for a good tune-up. I think it's worth it if you think of it like this; changing the oil in your car is, say, $30...replacing the engine is $3000.
You buy a really good machine, but if you don't take GOOD care of it, it's not worth all the money you paid for it.
And I agree with you about letting go of your machine...just the thought puts me on the verge of panic. So my solution is to take her (the machine) to the dealer for her preventive maintainence while I'm out of state on vacation, and make sure I get back home early enough to pick her up before I go back to the apartment.