I believe all MB dealers use extraction to change oil...and if you buy yourself an oil extractor and an MB filter wrench it really couldn't be easier. There is no demonstrated benefit to "pulling-the-plug".
svc "A" is one hour so their rate is probably $120 in labor and $60-ish on parts. It used to be, and don't quote me on this, that if you showed your receipts to the service dept that MB would update your vehicle records to show the oil change....I simply write down my changes in the service booklet.
Not true about MB dealers all using extraction. My dealership removes the oil pan plug to drain. The invoice bears that out because it lists a new crush ring along with the filter and oil.
I would never use extraction myself, or take a car to a shop that did, because I want as much of the used oil and wear contaminants out as possible.