I see where you are coming from but not quite.

What I am saying is that the process is already legal and available, so the process isn't a barrier to melting and selling the gold. I don't take a position on whether someone would simply not do it because its illegal.

The process of growing and selling weed was illegal, and thus also a barrier to accessing weed.

If anything your line of reasoning makes me want to legalise and protect melting gold you find and selling it.