I have an extra set of P50 Porsche Motorsports Greenpads - I paid about $620 for the full F&R set.

Traded them back to Craig at www.Rennstore.com rennstore@comcast.net when I got another brake setup.
E-mail him, not me, if you are interested.

He is selling them for $450 FOR BOTH FRONT AND REAR.
Cheap, folks.......cheap.