30,000 mile service - is it a good idea?

My car is due for a routine big service - oil change, tranny oil change, spark plugs, air filter, fuel filter, etc. Most dealers charge about 500 bucks for the "30,000 mile service" (its a 85, 190E 2.3, 130K miles), but basically, they do what I have listed above. The cost of the individual services would not be more than 250, add another 100 bucks (max) say for lubrication, inspection, road test, etc. still comes to 350. Should I just get the individual jobs done, or is there something in that "30,000 mile service" that is of value, that I haven't included?

All dealers list the same standard mercedes-benz description of the 30,000 mile service. And yes, I have tried to look for an independent mechanic, but the two in my area are really bad, so I have no choice but to go to the dealer for it.

Is there anything else I should get done at the 30,000 mile interval? The car has been regularly cared for the last 50K miles at least.

thanks.