Scientists claim antimatter is the costliest material to make.
[27] In 2006, Gerald Smith estimated $250 million could produce 10 milligrams of
positrons[28] (equivalent to $25 billion per gram); and in 1999 NASA gave a figure of $62.5 trillion per gram of antihydrogen.
[27] This is because production is difficult (only a few
antiprotons are produced in reactions in particle accelerators), and because there is higher demand for the other uses of particle accelerators. According to CERN, it has cost a few hundred million
Swiss Francs to produce about 1 billionth of a gram (the amount used so far for particle/antiparticle collisions).
[29]