Good Luck with the Mercedes.
They can also be a money like any cars, especially "Luxury" cars if you don't do your own maintenance. But with a new car, most items are under warranty for as long as you have the lease. Make sure brakes are included with the maintenance because they are pricey for a Mercedes.
I on the other hand don't buy new cars because I don't want to make payments every month and the high insurance associated with a new car.
My parents taught me to live within my means. If only my wife and kids would learn this lesson. LOL