USPS's competitors are the postal laws, dating back to 1845, which prohibit private companies from transporting and delivering letters or packets in competition with the Postal Service. There are some EXEMPTIONS, such as those for delivering newspapers, magazines, and urgent letters, but where competition is allowed, as in the case of urgent delivery, private carriers must charge at least $3 more or twice as much as the first-class postage rate.<quoted text>
Because by law they are banned from offering first class delivery of letters.
With increased volume the prices would no doubt come down.
The prices have to come down to acquire the volume.