Even if you have a totally ruined coin, it's metal content is still worth something, especially if it is made out of precious rare metals like gold, silver and platinum. The melt value of a coin is basically what the metal of the coin is worth if you were to melt the coins down. As of late, the prices of copper, silver and especially gold have increased by huge amounts, which have a major impact on the worth of the coin.
Much of the prices on our site are based on numismatic values, which are frequently worth many times more than the intrinsic metal value of the coin itself. US Coin Melt Values Current Intrinsic Metal Value of Coins