There are a number of factors affecting negotiation in purchasing. Supply and demand is just one. If demand for goods and services outstrips the supply, the inevitable outcome is that the price goes up until buyer price resistance begins to kick in, i.e. The price point at which demand begins to dry up. Conversely, when there is an over-supply of goods and services - a glut - then the tendency is for the price to fall in order that the suppliers can shift their goods and services and limit their loss exposure. No supplier wants to be left with goods they can't sell and cut profit margins to the bone in order to achieve this. Another factor that can work in the buyer's favour are such things as shipping costs and delivery dates. No one likes to pay over the odds for shipping, nor do they wish to have a long wait for delivery. These are both factors that can be used to lever a discount. Likewise is having a ball park figure in mind that you are willing to pay and a quote from a rival company.