brakes for 1991 200 20v turbo quattro

[larrye@cris.com (Lawrence Eisenberg)]

Hi all!
   A friend has a 1991 20valve 200 turbo quatro with 16k miles which has
developed a shudder on  braking.  He has been told that all the rotors are
warped (but the calipers are ok!) and has been quoted about $1600 to replace
the pads and rotors on all 4 wheels at the local dealer (who is not know for
inexpensiveness!). He checked with a reputable (but not really familiar with
this model) local garage, and they said that the brakes were of the
"internal" type and hence too complicated for them to work on and the quote
was probably in line.  Does anyone have any comments on this and does the 93
S4 which I am considering purchasing share this same complex and expensive
brakes (which in this case only lasted 16k miles)? Is it possible to work on
these brakes on one's own 9I have had an easy time doing brake work on my
4000Q at 70k), and where is a good source for parts ($.10 per mile for
brakes sort of gives me pause)? Is this sort of premature brake failure
common in this model, and should the calipers be suspected as well( the
dealer says no)?  Thanks in advance and your advice will be appreciated
                                               Larry Eisenberg
1984 4000s Quattro
1993 S4 (very soon I hope)