Rear Control Arms and Strut replacement is $4100 fair quote?

I have a 2013 Subaru BRZ that hydroplaned and hit its rear end into the highway barrier. It drives at a slow speed but rocks side to side. Taking it to the Subaru dealership they came back with:

REPLACE LEFT REAR STRUT, LOWER CONTROL ARM , UPPER CONTROL ARM WITH BALL JOINT, TOE CONTROL LINK

And a quote of $4100.

I would not expect such a high price for 4 parts all on one side of the rear wheel suspension system, but is this a fair quote? Should I trust or investigate other 3rd party mechanics for this sort of a repair?