I dont know where the $84 came from, my MB dealer charges that for a genuine MB filter and synthetic oil plus a carwash.
I am shure the napa filter costs $2 and at $1 a quart for bulk oil, it is a good promo maybe they lost $3 for the labor costs involved. Dont forget Jiffy lube coupons
If anyone is interested they do root canal surgery in Metamoros Mexico, walk ins welcome, just across the border.