Re: How much
"Bearing in mind they are working up a number of plans of which only one will be selected."
Also bearing in mind the one which will be selected probably won't work so the number will be at least one more than the number they first thought of.
Multiply that by the number of departments/ ministries and just for the hell of it, double it.
So the answer to your question while not precise is ; A bloody lot!
It might be cheaper to apply for 51st Statehood, although with the Tea tax they will levy that won't be cheap either