Lowe's, like nearly all appliance retailers, doesn't generally sell used appliances, as of 2015. Retailers typically purchase new models of appliances every year and have only limited floor space.
Like most retailers, Lowe's seeks to sell all of its appliances before the new ones arrive. As a result, they often offer discounts on appliances once new models have been announced. Locally owned retailers sometimes offer used appliances, as do thrift stores and other local businesses. Lowe's offers so-called "scratch and dent" appliances at some of their stores. These appliances are damaged enough to have failed inspection, but many only have minor cosmetic damage that might not even be visible once the appliance is in place.