I think this might be the crankcase breather problem that other people have posted about on here...Is so, anyone have a ballpark what it will cost to get it fixed?

The gist:
When idling I get a burning oil smell coming in through the vents.
The long story:

It has been a$$ cold here up in MN, below zero for the last week, luckily I take the bus to work so the X sits in the garage...drove the car about 50 miles roundtrip to a Super bowl party on Sunday, everything was fine...went out to do some errands last night, pulled the car out of the garage and let it warm up for maybe 5-10 minutes (I know BMW doesn’t like you doing this but its too darn cold to get in a cold car!)...everything is fine...leave the car running as I run into the drycleaners...get back in and it smells like burning oil...thought it was just a bus going by or something...drove, stop and go, for about 20 minutes, and every time I stopped at a light the smell would come back...stopped at the gas station and popped the hood, little oil around the oil cap, but checked the dipstick and all good, and nothing leaking under the car...all this time no warning lights turned on and the car ran normally...let it sit for about 2 hours then drove back home...it was fine until I parked it in the driveway and let it sit for a few minutes and the smell came back...popped hood but nothing doing...at this point it was late and freezing so I called it a night...