What you make with your very own hands is yours.
You can try to sell it for pretty much whatever price you ask. You can sell it to whoever you want to (in most states - in some states you might need to display a sign that says "we reserve the right to refuse service..." or jump through some other legal hoop. You can increase your production or go our of business, if you want. You don't have to sell it to anyone, if you don't want to - you can just keep it for yourself. It is yours.
I don't understand why you don't understand this. It is so simple. It has nothing to do with the Hunt brothers buying up all the silver they could get their hands on.