How Supply and Demand Impacts Real Estate Home Values How Supply and Demand Impacts Real Estate Home Values Some Highlights: The concept of supply & demand is a simple one. The best time to sell something is when the supply of that item is low & the demand for that item is high! Anything under a 6-month supply is a seller’s market! Nationally, there has not been a 6-months inventory supply since August 2012! Inventory levels differ depending on the area of the country and price range, so let’s get together to discuss the exact market conditions in our area.