Some companies cover sales tax for their customers or they do some trick to avoid sales tax, some don't. Some states require sales tax over online order. See ht

Some companies cover sales tax for their customers or they do some trick to avoid sales tax, some don't. Some states require sales tax over online order. See http://www.amazon.com/gp/help/customer/display.html?nodeId=468512 http://www.amazon.com/gp/help/customer/display.html?nodeId=4...