Using the CPI inflation calculator available on the Bureau of Labor Statistics website, indicates that a silver price of $28.80 today is roughly equal to $10.30 in 1980 dollars. Many believe the CPI Inflation calculator is an inadequate way to measure true inflation. The US Monetary Base has exploded since 1980.
Next, consider the change in global supply of Silver since 1980. Many believe the above ground amount of silver for investment has decreased by 50 to 67% since 1980.
As stated before, I think an argument can be made that silver may be the most undervalued asset anywhere.
