don't flush the trans,drain it.Do the diy in the diy section.Or find an indie to do it,mb spec fluid only.
Oil change MercedesShopWiki: OilFilter2
0w40 mobil syn and fleece filter
filter at Auto Parts at AutohausAZ - OEM Auto Parts - Discount Replacement Parts, Resources and Car Care Tips
Never go to the dealer
If you can't diy find a good indie shop,ask here on the forum some member will be in your area that has a place they trust.
Never go to the dealer ohlord
ball park dealer $300 at least for the trans and that might not include the filter
$175 oil and filter or they will most likely hit you for the A service at that starts at well over 350bucks.They change the oil and filter and look at your belts and hoses before they hose you
and whatever else they can suck out of you before they let the car go.
Me?what do I pay?Fluid ,filters and a few hours time,priceless