I have found, in looking through Craigs List and various other local listings, that there are not a lot of duck eggs for sale in the Leesburg, VA area.  I am not sure why that is, but am glad I have ducks that lay eggs year round so far.  They were purchased last July (2008) as day-olds and started producing eggs in December.  I am getting an egg a day per duck, and I have 10 female Indian Runner ducks.