Competitive on everything except the item they compared

A schedule of forty items is quoted. The buyer knows the market price of five of them and forms a view of the whole quotation from those.

Uniform margin is not optimal

Applying the same margin across every line means the visible items carry the same markup as the obscure ones. Competitors who understand this price the known items keenly and recover elsewhere.

You cannot learn this without recording losses

Most suppliers keep won quotations and discard lost ones. The lost ones contain the information — which items, at what price, against whom.

A caution

This is about where margin sits in a schedule, not about obscuring a total. A buyer who feels misled on the unfamiliar lines does not return, and the practice only works where the overall price is genuinely competitive.