USGoBuy offers USA shopping addresses from their warehouse in Oregon, this means that there is no sales tax to pay on your US shopping. There are no joining or ongoing fees and they have a simple fee structure where you pay for the services you use, such as repackaging, consolidation or photos.
They will even purchase the items for you using their US credit card as long as you prepay the money into their account.
You can pay using any credit card or Webmoney and PayPal, and they ship with a wide range of shippers.
USGoBuy.com claim that they can offer 85% off usual shipping rates. Their membership system means that the more you ship the cheaper the rates. This is calculated using the amount spent on shipments each year.
Payment of import duties is not taken care of, so may need to be paid upon arrival in your country.