Overall, cost differences will depend on the product, its quality and the existing market conditions. There are environmentally preferable products that cost less than their conventional counterparts. For example, several recycled printing papers cost less than virgin papers. Recycled plastic trash can liners (for commercial use) cost less than virgin because the postconsumer plastic resin currently has a lower market price than virgin plastic resin. The price of re-refined motor oil is now comparable to virgin motor oil. Also, many public agencies in the Bay Area and across the country have seen no overall cost increase after switching to “green” cleaning products. In addition, environmentally preferable products may last longer or require less maintenance than their counterparts. So even if there are higher initial costs, substantial savings may occur over time as a result. A variety of building materials offer these benefits.