Prices vary from very cheap to very expensive - basically you get what you pay for. Cheap sails range in price from less than $20 to around $300. These sails from Amazon or eBay and low-priced boxed shade sails from hardware stores will not last long. These sails will not take tension and will break on the edge or in the seams if treated like a real shade sail and subjected to tensioning. They will have no warranty. Middle range premade sails will start at about $150 for a small lightweight Residential grade shade sail 3M x 3M x 3M (approx. 9ft x 9ft x 9ft) and going as high as $900 for a Commercial grade shade sail of 5M x 7M (approx. 17ft x 24ft). The Residential not be used for tensioned permanent installation and should be taken down in bad weather and stored through the winter months. If well cared for they will have a useful life of 10 years or more. They will have a 5-year warranty. The Commercial Grade sails are designed to be tensioned and should last up to 18 years if well maintained. Warranty of 15 years.