Agree with what most folks have mentioned already. Without converting this thread into another maintenance thread - the cost to maintain will vary with the type of maintenance you choose. Factory vs Mike Miller's recs. I decided for the later (since I can afford it and plan to keep the car with me for 8-10 yrs)
Upselling, extra stuff vary with each dealership. My dealer wanted to upsell me with lots of things but I was "well informed" thanks to bimmerfest. Negotiated a reasonable price (500 above invoice).
I did go for the $600 interior and exterior protection plan by 3M (mostly because I was worried about interiors - oyster white). In hindsight, I may have skipped it and just used over the shelf leather cleaning products. I like to have peace of mind in knowing that if I have kids in the next 2-3 years and they spill stuff, I will be covered.
I did not go for the clear bra but did choose opti-coat. What a difference! my car looks like it has been waxed every day. Definitely consider this option (3rd party).
Do not go for the 28i. The engine feels like it is limping. I'm sure its good for many folks. I had my 1200 mile break in service today and was given a 528 loaner. It felt like I was driving a toyota avalon.
Get the DHP and sports seats. Once you have those, you will never want to drive a regular BMW again