Show item average cost in new invoice


I purchase inventory items from multiple suppliers and sell them at different prices depending on the customer and average cost change.
I’m wondering if a new invoice can show the average cost for each item in a column that disappear after submitting the invoice, this will help entering sale prices quicker that going back to “inventory items” to check to cost each time.

note: i don’t have fixed sale price, it is always changing depending on cost change