The TPMS is not unique to XF's or MB's. Lots of cars have them. Have you considered going to your local Goodyear store? (The one near my home is located across the street from the 4th largest MB dealer in the country. The MB dealer actually owns the property the Goodyear store is on but I digress.) That is where I purchased the F1's for my car. They used the "old" TPMS stems for my new tires (didn't charge me for new stems) and didn't charge me to reset the TPMS. You, my friend, are getting ripped off by the dealer. I have also been told that Goodyear is able to get excellent prices on parts for Chrysler cars (some sort of partnership they have going) and so if I need an out-of-warranty repair such as this, I would check with my local Goodyear store first. The day after I bought my XF, I took it by the store and asked if they could do routine maintenance on it. They said "What's the big deal, it's just a Mercedes and we work on them all the time." And I'm not saying it to make you feel bad, but it's these kinds of repairs (little things that cost a lot of $$$) that convinced me a long time ago to always get extended warranties.