Premiums are the price you pay above spot. Say spot price for silver is $18.00 per ounce your premium could $1-$1000 depending on the manufacturer. The premium covers profits, manufacture, distribution advertising of the precious metals you buy. Lots of bullion companies advertise they are only $xx.xxx above spot which most stackers like. Usually the more ounces you purchase the less your premium is which is why fractional coins and bullion are more expensive.
Currently at 57 Troy ounces!!!