I own a 2001 330ci which I bought brand new. I still have it and at 70,000 miles, it's still running strong. Original clutch and brake shoes. I drive fairly easy on the car because I like to increase it's longevity and to conserve fuel. But when you put your foot in it, it's revs very nicely and handles!
The only problems have been small ones. And nothing to write home about. I had the water pump replaced at 60,000 miles. The dealer found it was leaking, or weeping during the 60K service. No window problems, but sometimes the power window will close, then open down a few inches after it reaches the closed position. I just have to hold the button to fully close it. I figure that could be a dirty sensor. I have not looked into it yet.
Here's a great site you should join:
http://www.bimmerfest.com/
And this one too, though I don't go here much:
http://forums.bimmerforums.com/forum/index.php
In terms of dealing for a good price. When I bought my car, it was a total custom order. I didn't know any better really. I think some people managed to get a better deal then me. I just went to the dealer, and ordered the car. The color, leather, xenon lights (New at the time), Harmon Kardon sound system, moon roof, 17" M wheels, blah, blah, blah. I wished I ordered the navigation, but I thought I'd be prudent. Then I waited 3 months and it was shipped here.
It was my first BMW. So I went in and the car is priced based on what you want on the car. I suppose now in our current economic environment, you could try to deal with what they have sitting on the lot and get what you get.
One last thing, it was my first BMW. Before, I had a couple of new American cars. The experience of delivery probably varies from dealer to dealer, but the salesman spent about an hour going over the whole car and explaining all the features and how they work. That was nice. Though I paid for it of course!
Good luck!