At a recent Mavin Auction (2-3/11/2007) in Singapore, a King George V. 5 Cents 1920 Straits Settlements Silver coin choice uncirculated condition fetched a whopping USD9,000 price tag (excluding 15% buyer premium +7% gst). This coin has a 0.400 silver content with original mintage of 4,000,031( do not know how many coins left). This 5 cent silver 1920 coins can to a certain extent indeed can compare to the Queen Victoria 1889 & 1893 rare 50 Cent Straits Settlements silver coins and seems to fare better than the elusive 1/4 cent 1883 Straits Settlements coin.
Do not belittle even a similar coin but with very low quality condition which was described as with pitted surface, fine/good fine condition which realized US$200 before including 15% buyer premium & 7% GST.
However, the below brother which is of copper-nickel in nature ( King George V, 5 Cents, 1920, (KM.34), copper-nickel, weak strike obv., minor bagmarks obv., uncirculated) fetched a price of USD150 before 15%+7%