Got quoted ~$7000 to replace 4 dampers and 2 thermostats(Bryant). Any thoughts on the estimate?

~3500 sq ft home with 2 zones. For the past few days one of the zones was barely responsive to changes made on the thermostat. Being told dampers (x2) responsible for the zones have failed. And will need to replace all dampers and thermostats to fix.

Quote is for 4 dampers (2 per zone) and 2 thermostats. Current ones are 8-11 years old.

Any opinion on if this quote is reasonable or too high?