Cheapest for domestic mailing of a package of multiple discs is Media Mail, which charges by the pound. For single discs or two, First Class is a little cheaper and somewhat faster. Media Mail sometimes takes an extra 2-3 days to deliver, but sometimes it is as fast as First Class. Priority Mail might gain a day or two on delivery, but not always. It is best only when sending enough discs in a fixed rate box or envelope that it would cost no more than using First Class. Buy insurance for rare items. It is available for any domestic class. International mailing offers fewer options (no Media Mail) and is far more expensive. For international mail, consider sending discs and inserts without cases, and save half the cost. I usually use First Class for international packages unless the weight matches the cost of a fixed rate Priority Mail box, or if the buyer wants to pay the higher rate.
