Dealers typically sell them for $1 apiece. You would be lucky to get half that from a dealer. There are a few stamps, usually high values, that have a bit more value.
$1.50 (Scott Specialized Catalog of US Stamps 2011, page 405(First Day Covers))
Postage stamps are released on a specific day, called the First Day of Issue. Stamps cancelled on this date are the earliest usages possible. While special cancellations on special envelopes (cachets) are commonly available for stamps issued in the last seventy or so years, earlier stamps are much harder to find.
Britain has always had a portrait of the ruling monarch on their stamps. Canada pictured the ruling monarch on their definitive stamps, which pretty much means a living person has been on their stamps from the first issue with Queen Victoria.
There were no stamps in 1801. The first postage stamps were issued in Great Britain in 1840. It was several years after that that German issued postage stamps.
500 first class stamps would cost: Well it depends where you get them from!!! :)
Stamps were not available in 1812. The first where used in Great Britain in 1840. When the first US stamps camp out, they were 5 cents for the first 1/2 ounce of mail.
The Koreans do not issue currency in dollars.
$1.05
Learn english
About $0.50
My office is changing systems from a weight based postage to using First-Class Stamps. How much does a set of First-Class Stamps cost and is there any discount for purchasing in bulk?
Scott Specialized Catalog of US Stamps 2011 has a section for vending machine stamps. Titled 'Vending & Affixing Machine Perforations on pages 521 to 526. There are over 100 - 1 cent & 3 cent stamps in this section. Values range from about $1 to $1000's of dollars. Identification of these vending machine stamps are very specific for each stamp because of issue and perforations.