This morning I went to go get an oil and filter change on my Mitsubishi Lancer Evolution. Being mostly ignorant in the car world, I go to my dealership to handle any service requests on my car. I can hear you car enthusiasts grumbling now. However, it's just the easiest for me even if it costs me a bit more out of pocket. Half an hour into the service, the lady handling my car came to me and said the cabin air filter needed to be changed along with a tire rotation. Now first of all, I just purchased these tires, they have about 3,000 miles on them if that. Immediately I started questioning her since that didn't sound right at all. I had also told her, unknowingly to just go ahead and take care of the cabin air filter as well -- it sounded like something that was going to be a pain to do myself. Off she went to go double check with the technician on the tires. I quickly Google'd Lancer cabin air filter just to see what one would cost. One of the first results was surprisingly a video bashing dealerships for charging $50 (almost the exact price I was quoted -- $50.38) to change the filter for you and how to change it yourself in about 5-10 minutes.
So there you have it. By asking basic question and challenging these people, I ended up saving ~$70 today. I'll swing by the auto parts store on the way home, snag an air filter for $11 or so and do it myself tonight or this weekend. I knew dealerships were really stealerships!