My Macbook Pro 17" recently began to experience some strange problems (random clicking, trackpad "sticking", random shutdowns, etc.) and I have traced the problem to a faulty battery that has begun to expand. As the battery is now about 3 years old and has about 380 cycles on it, I assume that I cannot return it as defective, so where can I get a good, cheap replacement. Apple's prices on 17" batteries seem rather excessive.