I thought the present day ban on melting was only on nickels and pennies, due to the fact that they contain commodities worth more than their face value (that was how it was when the ban was enacted a few years ago when people were melting nickels and pre 82 pennies). I am not aware of any ban on melting modern dimes, quarters, halves, presidential dollars, etc.
States that tax PM sales are just being greedy for tax dollars. Most who buy PM's treat them like an investment, yet we don't see state sales tax on stocks, ETF shares, futures contracts, annuities, bonds, etc.
I think if a state wants to stop taxing PM sales it could be done legislatively without any mention of "legal tender" status, etc. In fact, I know of at least one state that taxes any PM sales if the value exceeds 50% of face value, yet that same state does not tax privately minted bullion/rounds.
If I lived in a state that taxed PM's I would be buying online or from private individuals. No way would I buy silver if in addition to the already high premiums I had to add another 7 or so percent.
Just my opinion.
Jim