It's part of the propaganda. Richest country in the world, they say, but you pay a lot more for basically everything because there's few government regulations keeping prices in check, and a number of things that are done by the government in other countries are run by for profit corporations here (healthcare).

Although, $10.50 for the mail is pretty pricey. That's no letter that they're sending. I run an Etsy shop and frequently send stuff in padded envelopes through the post office, and those cost me like $4 to send across the country.