If a currency is backed by gold, why would silver have value?
If currency was backed by gold it would actually increase the perceived value of all precious metals. Keep in mind, Silver is also used widely in industry such as semiconductors.
Silver is also a monetary metal. However, the silver market is much, much, smaller than the gold market. Since the metal is so "cheap", the amount of demand has skyrocketed over the last 12 months and the supply has plummeted due to a large sector of the mining industry significantly cutting back its production or has gone bankrupt altogether.
Another reason why a significant premium will be attached to the metal is that over 40% of the silver mined in the world is a by-product of other metals - lead, copper and zinc. Those mines have been closing at a rapid pace, thus the squeeze for silver is on.
Then why is it still so cheap? Because the rest of the world hasn't figured out that fiat paper isn't worth anything and when they come to that revelation, silver and gold will go "No Offer".
So would you suggest investing in gold or silver or both?
I would put it this way: Gold if you can afford it. Silver if you can't.