Those coins are worth a great deal more than $341,000.
At today’s spot price per ounce, it’s not likely the numismatic value exceeds the melt value, unless you see some rare coins in there, which I do not.
The article says the whole treasure weighed about 15 pounds.. times 14.48 = 218.7 Troy oz - times $3,247.4 = $710,206 melt value.
So, if the coins were half the weight of the treasure, that would make them worth $355k in melt value.
Based on that, the $340k seems reasonable.
Why do you think they are worth more?