No wonder Amazon decided to basically create their own logistic chain.
replyFedex/UPS cost for a single package is roughly ~$13.95 (this was ~5 years ago when I was working in ecommerce) and even if Amazon was getting a huge discount from them for the volume they do, it was still probably nowhere near $1/package.
That 13.95 price includes airplane rides too, it isn't just the last mile delivery.
reply999/1000 times if you track the package, it was going ground on a freighter.
replyThat price is generally way too low to include air mail.