http://wiki.answers.com/Q/How_much_does_graphite_cost_per_gram"
It cost $2.00 dollars per gallon of hydrogen. from: http://wiki.answers.com/Q/How_much_does_the_element_hydrogen_cost
$25 per milliigram $27000 per gram $70000 per ounce THESE PRICES ARE FROM 1937 finish reading the time article next time genius
Neptunium is not a commercial product, free for sale.
Neodymium is about $1 for a gram. It is not very expensive. It is used for coloring glass. It is a silvery color. My science teacher is so cool!