Derek,
My brother built a 3.5 Acre bottom land pond in the woods in the U.P., near Houghton. He got the DNR/NRCS office involved and said that they were very helpful. Most all my exposure and experiences with the NRCS offices has been extraordinarily rewarding. They are what you pay taxes for. I am in the middle of a 5a project and am using a contractor that used to be the CD agent, so I get both advantages. I am also going to get the NRCS office involved, just cuz. As my contractor would put it: "hey, you're paying for the service, so why not get their input?" They can and will do all the engineering, and provide the details of what to do and how much of it to do. The best part: It costs nothing and if you want to scrap their involvement, go ahead. You do want to remain very "hands on", tho. This is very much an "informed consumer" situation.
Regarding costs, as I have learned, efficiency=cost. If soil can be wasted VERY close to the excavation area, this is best. A dozer loses efficiency after pushing more than 125 feet or so. If it has to be trucked out, you are in the extreme end of the cost. Once again, this is where the NRCS can help with figuring how much excavation is required.
$20K for digging only for a 1.4a pond can only be cost-considered after knowing how many yards of dirt is being moved. Yes, it does sound kinda stiff, but how much digging do you want?
