The Samsung Galaxy S III is available at retail chains including Best Buy and Wal-Mart as well as online at Amazon.com and on eBay.com. The Galaxy S III is available unlocked and compatible with prepaid networks such as Straight Talk Wireless.
New Samsung Galaxy S III devices are available unlocked for between $150 and $225, as of April 2015. Used and refurbished Samsung Galaxy S III devices are widely available online due to the releases of the Galaxy S4 and Galaxy S5. Buying refurbished devices, which are used but have been factory repaired, is a good way to obtain Galaxy devices for cheaper-than-retail price.