https://www.yourmechanic.com/estimates/porsche/boxster/water-pump-replacement
This is an interesting site I've used from time to time to get a rough idea of what something might cost. Way way too many variables to make it truly accurate, but does give a general sense.
I also see $120/hour labour - that's very high - that's dealership labour pricing in these parts up North! ouch. My indy is $95 and he knows his stuff.