Moving Serial Unit of an Inventory Item onto Invoice and the price is not showing up.

Hello,

I am creating an invoice, I can move 4 items of an inventory Item to the invoice and the price shows up no problem.  When I try to move individual serial units of the item, the price does not show up.  For example - I have 10 Boxes at $1 a piece.  I only want to move Box A, B, C, D.  If I add 'Box' and set the quantity at 4, $4 is on the invoice.  If I try to individually move each serial unit, no price shows up.  Thoughts?

Thank you.

Best