Wow ^... my set of 4, including near new BMW pads, cost ~NZ$750 landed from the UK. I'm talking the blue M-Lite (M135i/M140i) Brembo from the F series though, they look better (IMHO), and are much lighter, than the E series performance brakes. A little more complicated to fit though.
If you're looking for used parts, it's a good idea to also peep at the for sale section of m3cutters in the UK, it's very active and covers everything BMW, not just M3's. Even better if you know someone in the UK that's willing to act as a freight forwarder.