Actually, Tx, I think the $540 was for multiple parts. Somebody correct me if I am mistaken...
and to answer the gentleman's question. I am still happy with my car. It's almost finished for less $$ than a hundya and I feel confident in driving it ANYWHERE.

Secondly I found a mechanic I am in love with (almost literally after my dealership experiences) He is well versed in Mercedes and charges $35 per hour !!WAHHHOOO!!!