Volvo Repair: S80 alternator/charging problem, routine maintanence, volvo dealer

Question
3 months ago, I had to replace the battery when my 99 s80 had starting issues (original battery).  The warning light associated with this problem wouldn't clear, but I didn't think that was an issue after reading some of the past postings.  I took the car in for routine maintanence about 3 months later.  The local volvo dealer saw the warning light on and decided to scan for codes ($100+ charge) without my consent.  Anyway, they found the battery issue in the codes and then checked the alternator.  They found low output from the alternator.  They recommended replacing the alternator for $400+.  My question, I decided to wait on the repair, as the battery replacement solved the starting issue with no further problems.  The charging light has never come on.  Is my Volvo dealer taking me for a ride, or should I have this work performed?  Have you ever heard of a weaping oil pan?  they wanted to charge me $600+ to fix that problem as well.

Thanks for your help,

Answer
Brian, yes its possible that the car has a Seeping oil pan.  These cars are known for oil leaks.  As far as the alternator issue, that is another problem that the S80's have but if you arent having any warning lights or messages, I would probably wait until you have another issue with the car.  Hope this helps.  Roger