USPS…….HOW MUCH?

Yet strangely we can get items with free shipping from China for $2, while USPS charges $10 for shipping the same within U.S. (Small Flat-Rate box). It would cost us $$$ to ship it to China. Has to do with international postage agreements. I've read that USPS is obligated to deliver foreign packages at no charge, with the shipper only paying Chinese postage. Supposedly, it balances out, but how many things get mailed to China? Perhaps we subsidize this deal via our much higher rates. I once shipped a manual transmission via DHL from CA to AZ for $70. It was also easy, I just drove to a nearby airport and they had me put the box on their conveyer with a label. But DHL stopped doing non-commercial shipping a decade ago.