I also purchased a set of Dunlop M3 RF from tirerack.com. I had previously purchased a set of Style 158s from the BMW Store in Vancouver.
They 158s look great on the car and the Dunlops are very quite and smooth, even up to 140kph.
You should either sell the Dunlops to your dealer (they can't buy them from the Canadian distributor for as good a price as you paid) and get the package or negotiate a discount on the 158s and mount the Dunlops. You should be able to get them for $499 each, list price is $623 each. My recollection is that BMW Canada is offering Bridgestone LM22 snows instead of Dunlop for the package. As you probably know, the Dunlops are the better rated tire.
Good luck with your negotiations.