[Jared at Pelican Parts]

The E24 is a nice car if you get one that is in good shape and has been maintained correctly. The drivetrain and suspension are pretty much all E28 5 series. However, all of the body and interior parts are E24 specific and the prices will add up quickly.

I've owned both a 635CSi and a 633CSi. They are nice cruisers, but keep in mind that it is a big car and for the most part will handle like so. The M6 is a whole other beast. Figure double the cost for engine parts. 27K is about on the mark, I'd say.. Nice thing about the M6 is that you can get close to 50HP by adding a chip.