Ahhh! That' sounding a lot better.

But just re-read xvvvz's post:

If you are willing to DIY, you may be able to fix things by replacing the voltage regulator/brush module. If you read lots of MB forums, you will see mulitple posts that these alternators are often misdiagnosed as needing to be replaced when often all they really need is to have the regulator replaced. Its only $24 and the procedure looks pretty basic according to the Haynes manual.
If it is just the voltage regulator/brush module, your mechanic can knock another $200 off the quote. If it really is the whole alternator, then the quote is now fairly reasonable.