Mt. Sinai charging me $2400 for colonoscopy AFTER insurance ($12k before insurance), even though I have a very good health insurance plan (I pay $1600 per month). Does this sound exorbitant?

They dropped this on me five days before the procedure. Does this sound exorbitant to anyone and is there a way to negotiate it down? I have a United health plan with total premiums $1600 per month which I thought was very good.

I am 33 years old with no symptoms btw.