Sellers should never give price breakdowns. Buyers should always try to get price breakdowns. The less a seller tells the buyer about their costs the better off they are. The more the buyer knows about the seller's costs and profits, the better their negotiating position. With respect to cost data, what is good for one is generally bad for the other. Sellers should start their negotiation on the basis that cost and pricing methods are nobody's business but their own. A buyer is well advised to insist that part of the price paid is access to full cost and production visibility. They have the right to know what they are buying and why the price is right.