Put your ad in Craig`s List...Duck eggs wanted, in the farm and livestock division. Also in your State fair division there is a poultry division. People that take their birds to the fair also may have some for sale and could bring them there for you if they know you want them. If you check your Craigs list and check for duck eggs, you may very well find your fertilized eggs or ducklings.
There are people right here on this BYC that have what you want. Just let it be known.