The seed of an idea for trading silver/gold

I don't have any financial savvy.
But I have an idea that I think , if injected with financial savvy could be a good one.
A silver/gold trading club.
Whereby a certain amount of silver/gold was bought at or near spot. And those in the club agreed to never sell outside the club or above spot these particular bars/rounds whatever.

Then buy or sell to each other in an effort to gamble on rising or falling spot price.

The advantage of such a scheme would be that you would not be investing in the debt money world where the ATO can stick its beak in. So its pure profit . You can forget about premiums and concentrate on just spot.

A trusted 3rd party can hold the actual bars to save on postage, but they can be sent to the buyer if requested.

Might be more interesting if you could put margin buying into the scheme somehow, but I can't think how that would work.

In essence it is taking possession of lawful money or losing possession of it, and therefore untaxable.