I had a 320d Touring, but TBH I don't know how much main dealer servicing cost as mine had a full service pack included – all servicing up to 3 years / 60k miles paid for up front by its original owner (the BMW fleet); when it passed 60k miles I started getting it done at a local independant garage and it wasn't too bad.
39mpg on average including a 30 mile each way commute across Leeds / Bradford; when I changed it to my current car, a Saab 9-3 diesel sportwagon, I was getting the same mpg until I changed my route to not go through the centre of Bradford, so the low mpg is more down to the stop-start nature of the route than my driving style
I don't remember any snow in the 4 & a bit years that I had it but having seen another RWD car sliding about last winter I can imagine it wouldn't be good.
Apart from the original purchase price and the fact that the boot is too small for my particular needs, I'd have another
But thinking again, if you're only doing 8-10k miles a year, do you really need a diesel?