What year and model? How many miles? Yes, the A service is a glorified oil change, but there are a few things that should be done too, depending on your model. For instance, on the W202 C-Class, you should change the cabin dust filter every A service. It's an easy DIY, though.
30,000 miles for a tranny service? Do you have the 722.6? It's intervals are MUCH longer. What engine do you have? 30K for plugs is pretty often, especially for the 112/113 engines. For the M104/102 and such, it should work well. 30K tranny services are right for the four speed auto-boxes.
1998 C230 "Black Betty"