Some of those prices seem way over priced.
Hankook W300 icebear can be had for $700 all-in.
Barum Polaris 3 can be had for $655 all-in.
BTW, I don't recommend getting the General's or the Dunlop's for your vehicle. The compound is a bit soft for the power of the 335i. For your vehicle, get at least a T-rated, preferably H-rated or V-rated winter tire.