Yep, I agree with Mark. I use a local rebuilder for my alternators and starters and have been pleased with the quality of work. The parts get a good going through and for less money in most cases.
I'm afraid to quote Baggins987 for fear of triple posting

but I had a core issue at one time. My starter on my Pontiac went out one Friday evening in a restaurant parking lot, and for convenience, my husband installed one from Autozone and handed them the core. The starter worked over the weekend, then broke Monday. Since I worked at a GM dealership, I replaced it with an Ac-Delco and took the faulty one back to Autozone for a refund. They didn't want to refund my money, saying that starter had a lifetime warranty, but I finally convinced them the warranty was useless if I had to replace it every three days. Then, I couldn't get them to understand I should be reimbursed for the core, too, since I turned in two starters.
