2004 Chrysler Town Country Car Been Making Grinding Noises While Both Places

The car has been making the grinding noises for a while but both places that I took my car to said Chrysler cars make those kind of noises when the car is old. The car was bucking a little bit, like it was going to stall but it didn't, then later the engine light came on. My technician said I need to replace 2 sensors and a solenoid pack, including labor and tax, is $472. Does this sound right? Jack Williams is the place of service.
Thanks, connie