Oh, I'm not saying give a bunch away, just 1 per possibly customer. I haven't eaten duck eggs for decades, can't even remember the taste. You give me 1 egg to try...I like it, I'll buy.
Local farm produce was selling peaches. They had a sign take 1 sample, I took one, a bite and said, I'll take 2 packages. They were and are yummy.
Check on your city/state laws. In Ohio, we can sell eggs in small amounts/dozens, for backyard chicken keepers. They must be dated for when laid. A neighbor has a small stand in their front yard. They are not washed. The sign asks people to return the cartons. They put a label with label: Date Laid 7/27 & 28. Easy to peel off for a new label. I would do that but I take about 10-16 dz eggs to Church every Sun. Ours and our neighbor/friend, who started us with chickens. Most weeks, we have to turn people down. Some give $20 in advance and ask to have one dz a week.