I paid 31k for a fully loaded 04 3.0 roadster back a little under 3 years ago. Granted, it only had like 15,000 miles and was CPO, so that jacked up the price a bit (i looked around, price was fair at the time).
Changing the oil is easy. Brakes too. I'm at about 67,000 miles, and it's been a blast. My only complaints are some rattles in the interior, and I did have problems with the convertible top. It had to have the hydraulic replaced, twice. Since they had to pull the top apart, twice, it has some rattles and creaks in it now. I've bitched, because it's a small cabin and I hear all the noise because its right behind my head, but I just turn up the radio and drive.
I love the car, and chicks dig it.
I also hit a deer with it last june, and did about 7,000 in damage. Since it needed a new front bumper, I elected to pay the difference on the Aero kit, which is a more aggressive bumper cover. I also put on the aero skirts. Makes the car look alot meaner, imho.
I got to give props for the windshield quality though. It saved my life. You can see where the deer landed after I hit it in the following pic. You can also what the original ground effects, or lack there of, looked like. A pic of the car after the body work 2nd. The sideskirts flair out, which really helps the appearance.
http://i617.photobucket.com/albums/tt257/jasonallen19/z4/BMW20002_caption.jpg
http://i617.photobucket.com/albums/tt257/jasonallen19/z4/IMG00217.jpg