I'm sure the answer is it's a Carter Duck, but I figured it bears asking... Is it an original Kamikaze Shooter? A hybrid? or a Carter Desert Duck? If it's an original Kamikaze Shooter please PM me there phone number and I call dibs
Even $2500 for a hybrid (Carterized Kamikaze Shooter) is still a hellofa deal...
And as pk said, for a Carter duck, it's a fair price depending on how it's set up (in-grip, slam-changer, back-bottle, insertable barrel? etc...)
There are more knowledgeable persons on this site than I, but that's my personal answer to your question.