> "Germanium differs from silicon in that the supply for germanium is limited by the availability of exploitable sources, while the supply of silicon is only li

> "Germanium differs from silicon in that the supply for germanium is limited by the availability of exploitable sources, while the supply of silicon is only limited by production capacity since silicon comes from ordinary sand or quartz. As a result, while silicon could be bought in 1998 for less than $10 per kg,[20] the price of 1 kg of germanium was then almost $800.[20]" So nearly 2 orders of magnitude price difference. In 1998 admittedly, but still. (Someone should come up with a better example for the Wikipedia article)