[Negotiation] How do you think about total cost of ownership instead of just unit price?

I think of total cost as the price of getting and using the item successfully, not just the invoice number. That includes freight, quality fallout, service failures, internal handling, lead-time risk, inventory burden, expedite pressure, and sometimes the cost of managing a difficult supplier relationship.

That is why I do not like letting a sourcing conversation collapse into unit price alone. A lower price can still be a...