It's a moment, the salesman is waiting for when the prospect gets interested in the product and start a discussion about the product feature and pricing. An opportunity moved forward to proposition stage as prospect starts a discussion about the product pricing, the salesman should identify the decision makers, requirement about the products and its features, the delivery time so that salesman can do the better negotiation on him a later stage.
Let's create the products, and send the first proposal to prospects, start negotiating on the proposal and get it confirmed online with customer's signature.
