I'm sorry. I guess I don't understand.
I'll sell coturnix eggs for $3/dozen FOB my house all day long, until I have no more. As long as you are willing to stop by here, provide your own egg carton, and peddle your own eggs and butt home. If I need to pack those same eggs in cartons (which are not free), secure them with packing material (Which is not free) and ship them from here to you via USPS.....WHICH IS NOT FREE....would cost you $3/dozen for the eggs...$1.75 for the packing material/egg cartons, and what ever it cost me to ship that package from point A (ME) to point B (YOU). Which depends on weight and distance.
Let me do the math here...It's not complicated.
Pick up 3 dozen coturnix hatching eggs from here... $9.00
Ship $9.00 worth of coturnix eggs from here to there....
$9.00 for eggs+$1.75 for cartons and packing material+what ever it cost to ship from me to you....An average of $8.00.
That would be... $18.75
Divide that out properly, and the delivered cost is roughly...$6.25/dozen