Buying Advice - Volvo V70 Vs. Mercedes E320

I'm having a baby and I don't like SUVs or Minivans. My search has
been narrowed to these two wagons. Volvo is a favorite given its
safety, Mercedes is considered for safety and everything else
Mercedeses are all about.

I'm faced with the following questions:
1 - MAINTENACE - If the price of the cars is about the same, is
maintenance any different? I'm hearing scary stories about regular
oil changes (usually priced about 30 for my Honda Accord) are about
$100 for Mercedes since they use Synthetic oil.


2 - TUNE UPS - Is the price of a full tune up (spark plugs, wires,
gas
filters, etc) much different on a Mercedes. Here I'm once again
being
scared with 200 for my Honda versus 600 for a Mercedes. Is there any
truth to this?


3 - Now the most important question, notice how I'm comparing
maintenance expenses with a Honda. Is the maintenance on a Volvo
cheaper than on a Mercedes?


4 - What should I look after when purchasing an E320. What are the
next huge schedule maintenance, say at 100K.

5 - Which of the two cars tends to hold on to their value better.

6 - What other reasons should I consider when choosing between these
cars?


By the way, the reason I'm getting a Station is my dog and the 3rd
seat I use with all my nieces and nephews.


Thanks for all your help.
Will
NYC