Economic Question; please help

So I'm reading Atlas Shrugged this week. I have to ask, because for the life of me, I can't figure it out:

If we...

• ...want to have metal as money...
• ...possess the Freedom of Contract...
• ...want to encourage economic success within the ranks of others with this idea...

...then why have I never seen any of the local businesses willing to contract in terms of metal? I understand about Gresham's Law, but it seems that it would be possible for both sides of the transaction to be favorable for the purposes of tax avoidance and anonymity.

For instance... A restaurateur runs an establishment that charges roughly $16 for a meal served to the patron. He happens to be a man of the Ron Paul persuasion and sees metals as a superior form of money and currency. If patrons paid in silver or gold, how could he be liable to report it to anyone? Because of the fact that the dollar is decoupled from gold in all respects, it might as well be a barter transaction. Thus allowing for income tax-free (until he converts the silver to FRNs).

A patron with a parallel political attitude toward money might be willing to spend some of his savings that has appreciated, rather than use his FRNs. He gets his $16 meal for $10 saved in January. He may even get it cheaper than that, because the restaurateur, now free from tax burdens, could offer the meal at a lower price.

Has anyone seen in real-life what I am describing? If not, why do you think that is?

I setup a simple forum that has the organizational flexibility to serve the role of linking buyers and sellers. It seems like rival currencies are popping up these days. Why not cut the crap and go straight to the real thing?