Cost of setting up the tender which is not a cost of the item itself.
All the other costs are related to the item itself.

Other customer data.
It would, I think, be very unusual for a contract manager to feel it appropriate to ask for information from a supplier representative about other customers. Business partners normally want their dealings to be private. However, in informal discussions, in the normal course of conversation, information is often transferred in a benign manner.

If it's included with the goods, it's likely to be a delivery note; and the buyer's equivalent would be a goods received note.

Specification creep - where the requirement becomes more complex or sophisticated than originally thought necessary for the buying organisation's purposes. Naturally, this can be expected to increase cost to the buying organisation.