Broken front spring perch
 

Hello everyone, I am a new member and I have a big problem that hopefully someone can help me with. I have a '97 E300 with up to now 130,000 trouble free miles. Today as my wife was pulling into the parking lot at work, she heard a loud noise and the left front of the car suddenly sagged. After arriving to check the car out I found that the left front spring perch was broken along the weld and was bent up at approximately a 60 degree angle. The front spring was completely seperated from the perch, resting between the front tire and wheel well.
The area where the perch is broken is corroded. This is especially troubling to me since being from the midwest I am very aware and take extra precautions to rinse the underside of the car of road salt and other contaminants. Is corrosion in this area a common problem on this car? The structure that the perch is welded to also appears to be corroded, is this going to be a big problem to fix? We have not hit anything abnormally hard with the front end of the car as the failure of the perch appears to be caused by the corrosion.
Could any of the expert techs give my a rough estimate of the worst case scenario, that being the structure around the perch is corroded and needs to be replaced along with the perch itself? Can I assume that the right side perch's failure is imminent? Thank you for your time to respond to my problem as I hope that the car can be repaired for a reasonable dollar amount as both my wife and I love the car.