Just a heads up on oil change. Every Spring and Fall NAPA runs a monthly flyer special on Mobil spec 229.52 oil. Found that out courtesy of other posters here. This past September it was $5.99/qt. You will also need a oil filter wrench (check ebay), to spin off the oil filter canister cap. That's about $78 bucks oil cost plus tax. Doing it yourself saves you about $120 bucks +/-, for about 30 mins work, using your example of the $75 labor add.
Some advice, if your so inclined. Measure the amount of oil removed, by pouring the spent oil into gallon jugs (milk, etc.) that way you know exactly how much new oil to add. MB sprinters are notorious for holding some oil in the motor, pan, etc. unless your unit is completly level during the drain cycle.