$4k for a Ball, no thanks. I'd definitely get an IWC at that point and it looks better, even an Omega. Besides a watch with the BMW logo will likely have bad resale or not hold value, like all other car type watches, except in the situation it's some die hard fan who loves everything of that brand.
You may find some here, play with the search feature:
http://www.watchrecon.com/?query=ball+bmw