Minting costs fluctuate all the time as their main factor is the prices of metals.
In fact, the only constant in this ever-changing market is that manufacturing a penny is never cost-effective. While its face value is – obviously – one cent, it costs almost two cents to manufacture.
In 2011, the new USA penny – which is in circulation since 2010 – reached an all-times peak-cost of 2.41 cents!!!
Bonus fact 1: At present, a penny is composed of 97.5% zinc and only 2.5% copper, which is much more expensive. However, save from 1943, pennies were composed of 100%-88% copper.
In February 2011, when copper prices soared, the melt value of pre-1982 pennies was more than three times its face value!!! In other words, you could have melted it and sell the copper for a profit.
Mind you, copper prices are currently (March 2021) closing in on the 2011 record.
Bonus fact 2: During 1943, due to wartime (ww2) shortages of copper, pennies were made of zinc-coated steel, wich are also known as the 1943 steel cents.