How much is a repair on a bmw 325I alternator?

I was hoping a mechanic could give me advice-BMW 325i

2002 Car wouldnt start i replaced the battery and car was fine. A week later the car wouldnt start even after i tried to jump start it / I had it towed and the mechanic says i need a new alternator total price 900.00. Is this a reasonable cost for the repair . How do I know if they have put a new one in and not a rebuilt oneHow much is a repair on a bmw 325I alternator?$430

http://repairpal.com/estimatorHow much is a repair on a bmw 325I alternator?I'm not 100% on bmw's but that sounds pretty outragous to me. $900? You can buy one for a ford new for 50. Try calling around to local part stores and get a few quotes. Use a rebuilt one over a new one, they are just as good and the chances of getting a bad one are no worse than the chances of getting a bad new one. As far as labor and installation, look at the motor, locate the alt. and just look how much work it would take to remove, they are almost always on the side of the motor and held in by 2 or 3 bolts, i can change one in 20 minutes. If you live anywhere near Eau Claire, Wisconsin go to Big Als Used Tires, tell them Jason sent you and your labor will total 50 bucksHow much is a repair on a bmw 325I alternator?I just had one replaced on my BMW and the total cost for replacement with a rebuilt alternator was $500. This was at an independent garage that specializes in repair of European cars. I would not worry about rebuilt alternators. They should last just as long as a brand new one and cost a lot less.