Runaway inflation

A rare five-dollar gold piece and a prized silver dollar each could fetch $10 million (NZ$13.5m) or more in upcoming auctions, making the American rare coin market as attractive, though not nearly as glamorous, as fine art.

Sales of rare US coins reached a record of nearly $536m last year, and now collectors are turning to the D. Brent Pogue Collection, which could boost it higher.

Gathered over more than 30 years by Texas property developer A. Mack Pogue and his son, D. Brent, it is considered the most valuable collection of federal American coins dating from the 1790s to the late 1830s in private hands.

An 1822 Half Eagle five-dollar gold piece, one of only three known to exist, and an 1804 Silver Dollar dubbed the ‘‘King of American Coins’’ are expected to be among the top lots when the collection is sold in a series of auctions in New York beginning in May and continuing into 2017.

‘‘These two coins in particular, we think, have a possibility of being up around that $10 million mark,’’ Brian Kendrella, the president of Stack’s Bowers Galleries, said.

The rare coin and currency auctioneer, which is handling the sales with Sotheby’s, believes the coins could shatter the $10 million record set in 2013 for a 1794 Silver Dollar.

Coin sales are driven by the economy, but Kendrella said investors and collectors are also lured by the rarity, uniqueness, condition and historical links of coins.

‘‘They are artefacts that speak to what was going on in the United States at the time these coins were made,’’ he said. ‘‘That’s one of the main draws.’’