Yes, silver is trading at about one seventieth of the price of gold, whereas in the era of coinage based on precious metals, it was about one fifteenth.
Thus it could be argued that silver is now massively underpriced, but if that were really the case this "anomaly" would long since have been corrected as "knowledgeable" buyers flooded in to take advantage, thus forcing the price back up to somewhere near its former ratio vis a vis gold (ie to about $80 per ounce).
And if it's the price of gold which has been anomalous, it should by now have fallen to around $200, as opposed to $1100.
It seems clear that the old ratio is no longer valid, and it is by no means obvious that it will be re-established.
I believe that "fair value" for gold is around $1200 per ounce, and for silver around $20.
Yes, silver may well spike to $50 or over in the next few years, as in 1980 and 2011, but these spikes are driven by speculators and are very short-lived. You have to know exactly what you're doing, move quickly and have a buyer who is willing to pay you the market price (very few will).