1. $100 for an oil change is high but not by much for synthetic these days
2. The air filter (it's a Mann) is like $40 from eBay or Pelican Parts and takes five minutes to change. The cabin filters (also Mann) are a pain in the butt to change, but doable, and are another $40. So you paid an extra $80 for labor there.
3. $200 for a vehicle check is highway robbery and whether or not they actually check anything is a crapshoot. I typically waive this service and reset that particular service light myself. I inspect the car pretty regularly myself, though I understand a lot of people don't have the time to do so.

Conclusion: Dealership service departments are expensive. Sometimes it can be worth it, but you have to do a little homework. Do some research online, see what people are saying. The most important thing you can do is ask to be shown the service bay and see both what kind of people are working back there and what condition the shop is in. If it's a bunch of kids and/or the place is a mess- you probably would be better off at an independent mechanic. If everything looks like something right out of the brochure, maybe the extra cost is worth it to you.