The Dinan camber plates cost $199 and add 0.7 degrees negative camber. They use the stock rubber bushings, which are soft and quiet. All other camber plates I've seen replace the stock bushings with solid metal, which is firm and noisy. Based on this, some people recommend Dinan for street and other camber plates for track.
I think it's worth pointing out that the M3 Front Lower Wishbone Kit costs 195.73 at HP Autowerks. It adds 0.75 degrees negative camber and includes stiffer bushings than the stock wishbones, which adds some front end firmness without noise.
Anyone feel free to add or correct if my apples to oranges comparison is over-simplifying anything.