'95 Sport 90 A/C Woes

[Mark W. Byrum, Jr.]

Dear List:
    The A/C on our '95 Sport 90 failed suddenly last week.  Pulled into
the driveway after a trip with everything working fine.  The following
morning, got into the car and smelled a strong musty, moldy odor.  A/C
did not work  Compressor engaged, blower worked, but no cooling.  Later
learned that we left a green liquid on the driveway where we had been
parked.  Just took the car to an independent Mercedes/Audi/Porsche shop
this morning (the same place which replace two seals somewhere in the
system and recharged it with R134 and dye 3 weeks ago) and received the
call that the evaporator has gone bad and needs replacing.  Approx.
$1000 for part, $800 for labor.
    Is this reasonable (both as to diagnosis and price)?
Your input is greatly needed and will be greatly appreciated.
Mark
'95 Sport 90
'86 4kcsq