I replace brakes (pads & rotors) often enough that I received a free t-shirt along with a hand-written note from the manager of my rotor supplier today!
They do make very good and affordable rotors! I have probably gone through 15 sets of rotors without any problems over the past 5 years.
For example, OEM replacement rotors for early Boxster's are $48 rear and $53 front (ea). That's a full set for $202 with free shipping. Check them out at:
Performance Brake Rotors | Brake Pads & More | Cquence.net