What concerns should you have when changing the alternator on a 2001 VW Jetta?

I have a 1999 VW Jetta GLS 4 cylinder 2.0liter SOHC New Body Style. My Alternator died, according to the technician at the VW Dealer. The electrical system diagnostics done by the tech indicated that the alternator was producing only 10amps and should be producing something like 14 amps. Backing up a bit; during the morning of the failure, my battery light went on. Later that night, I noticed that all interior lighting (including instrument dash-board lights) went dim. Additionally, the brake, ABS, airbag, etc. lights went off and a beeping noise occured. Long story short, my car started to sputter and eventually died on the highway. When I tried to start the car, the engine would barely turn over and the instrumentation lights flickered rapidly. I called around and found that PEPBoys or Advanced Auto Parts had Bosch alternators that fit my car for like $250. Bosch alternators at VW Dealer Parts Department costs $500 minimum. I'm not sure if it's the same one, but the VW guy on the phone said "Bosch". You do your own reasearch. Labor is 1.5 hours. Total from VW Dealer was around $750.00. I'd like to hear the experience of others as well.