Prices range from £10 for the uncirculated coin to £1,995 for the gold proof two-coin set.
David Pearce was just 15 when his design for the coin was chosen over more than 6,000 other entries in 2014.
David's design, which features national emblems of the UK - a rose, leek, thistle and shamrock - emerging from a Royal Coronet, has been slightly refined with the support of renowned coin artist David Lawrence and lettering expert Stephen Raw.
Dr Kevin Clancy, director of The Royal Mint Museum, who helped choose the design, said: "The winning idea combined traditional elements but also symbolised a modern United Kingdom in an elegant and a succinct way.
"It was a young person's interpretation of an idea while still being steeped in history and tradition."
The coins will be released for general use on 28 March and the old pound coins, which have been around since 1983, will cease being legal tender on 15 October.
The round pound's successor is thinner, lighter and slightly bigger in diameter - and experts believe that its distinctive design will make it trickier to counterfeit.
It has been estimated that about one in every 30 pound coins currently in circulation is fake, creating a headache for businesses and the Royal Mint.
The 12-sided pound has been heralded as "the most secure coin in the world", as it boasts several security features - including a holographic image which changes from a "£" symbol to the number "1" when the coin is seen from different angles.
The collectors' edition coins can be bought from royalmint.com