It depends...  on what services have been accomplished prior.  BMWs don't
have a straight mileage based service schedule.  They occur dependant on the
Service Inspection (SI) indicator lights.  Typically you have SI #1 at ~30k
miles, SI #2 at 60k, then back to SI #1 at ~90k miles.  But if nobody did
the SI #2 at 60k you'll probably want to get that done now.

Now all you need to do is ask how much an SI 1 or SI 2 costs from your local
stealer (or better yet local independant BMW specialist).
-Fred W