The price of a Tiberius coin should not stay far below the intrinsic value because of economically rational incentives.
Tiberius and other market participants will always be willing to buy a Tiberius coin in the market for almost as much the underlying metal can be sold for (i.e. the intrinsic value).
When the Tiberius coin is too cheap you can buy the undervalued token in order to obtain the metal, which can then be sold higher at a profit (this is called “arbitrage”). “Free money” doesn’t exist for long – as competition increases so does the strength of the price floor.