Yes this would be brilliant so what are some of the hurdles of setting up this service?
I'll start. If you were to send $6800 (10oz Gold) to a book. You wager for a while and you break even at $6800 and request a payout of your $6800. But gold has dropped in value to say $580 per oz. The book would have to send back way more than the 10oz you had originally sent. So not only would the book be in the business of booking bets but also forced to hedge their post up cash (gold).