If you do it yourself then it is quite cheap.
I sell the oil and filters. (Febi)
If you go to an indie, again reasonable.
If you go to the Main agent then I would suspect it is pricey.
And it may be the case that on your gearbox you cannot drain the torque convertor. I changed the oil on my S Class but could only get out 3.5 ltrs of the old stuff out of a possible 8 'ish', so have changed it a couple of times and plan to do the same at the next service.
What really annoys me is that some dealers charge for replacing the whole lot , say 8.5 ltrs when in fact they have only replaced 3.5 at over £10 for the branded MB oil.
They seem to get away with it and it is straight forward theft / deception.
That's why I always do my own work or a reliable and trustworthy garage when I am too busy.
My car had progressed more than how you describe your problem and seemed incurable. Foolishly making the assumption that it had 'for life' gear oil, this was overlooked. Immediately following replacing some of the oil there was a fantastic improvement and another change saw the problem virtually wiped out.
I am not guaranteeing this will cure your problem but suggesting that this is where you should start assuming you have ruled out other possibles such as wheel bearings etc.
