Lakes Region Marine, now Ambrose Marine, built my breakwater in 2010 for about $30K as well. They use a picture of it on their
web site. I thought we had a lot of rocks too but our water drops quickly to almost 20' by the end of it they had to bring in barge after barge. Their "rock guy" at the time really knew his stuff. It was fascinating to watch him fit each stone into place.
Mine is in an area that is not in the
designated zone and I can tell you from experience that if that's the case they do not just mysteriously appear. If memory serves you have to prove continuous waves of 2' or more lasting 4 hours or longer on 4 separate days between May 15 and October 15. Even if you have those conditions regularly its really tough to prove it. The wave heights are tough to judge from a picture.