How much does it cost to maintain your BMW 330i?

I purchased a 06 330i last week. The dealer "Cunnigham BMW" the worst dealer ever cheated me on the maintenance upgrade for 6 yrs 100k miles for $2600 bucks. They said i could change my mind and get the package off my BMW if i thought i didnt want it at a later time. I am trying to find out if 2600 bucks is worth for 2 years of upgrade?|||all bmw, audi, and vw's always are a pain to fix, costly and time consuming