I used to work in one of the chain auto parts stores (part time weekend gig). In our particular store we had 2 levels of parts available. The ones you knew were most likely bad right out of the box, and the ones that would be back after a longer period of time. Lets face it. What kind of alternator can you really be getting for 24.95 + tax and core. I did not purchase my parts from even my then employer. Of course you can get a bad one that is built by a reputable company. It happens. The last time I had to have an alternator I took mine to a guy that had a company that all they did was rebuild alternators, generators, starters and electric motors. Probably not an option for most but once he rebuilt or rewound something, I never have had to replace it. The alternator that is currently in my antique Mercury was redone by him 15 years ago. Still going strong and 45k miles.