GEEZ..give it a rest already.
OP..Maranello BMW by far has the cheapest OEM oil that I can find in the GTA.
I use The Castrol Syntec 0w30 European Formula oil that can be found in Canadian Tire. This is BMW approved oil and is a true synthetic oil. Seems to work great in my car with my particular driving conditions and performance modifications.
The key is to purchase this oil when it is on sale, otherwise it can get pricey at regular price ($10-11 I believe).
For the most part, I do all the work on my car.