The price quote, just a little over $2k, seems pretty reasonable for all that work. I expect they are giving you some relief. What does the shop say caused the damage: overheating?, or serp belt broke & jammed cam belt? One suggestion, in the future when work is needed on your car, post here for ideas first. I expect you would have rx’d a recommendation that both the idler pulley and tensioner be replaced along w/the serp belt.
They said the damage was caused by the tensioner breaking.