I bought some brake pads from ****************************************.com and they were about 200.00 or so. I bought the ones my mechanic told me to buy as they were better than OEM. Can't remember the name, but I know Pagid makes good ones.
My mechanic did a brake job for $175, including bleeding the brake lines completely and refilling the brake lines with new synthetic brake fluid... it was fairly expensive, but I can brake on a dime now.
Replacing brake pads on a Boxster is evidently very, very easy and quick. The problem is the rotors... they cannot be turned, only replaced. So every three or four pad replacements will also require a rotor replacement as well. They aint cheap, and labor is going to be more as well.
I guess we could all drive slower and get more miles out of our brakes. NOT!