would there be a difference in the lease price of leasing a bmw in november as compared to leasing a bmw 335i in december? if so, how much?

It is impossible to tell you that now. The current programs go to the end of november. The way the 335i has been selling, i doubt it will go down. BMW thinks they are within a great price point compared to their competition, and i agree. They are up in sales every month, and are showing no signs of slowing. Get it now.