About two years ago it was really necessary to give 2000 XAUR for 1g of gold. The ratio changes in favor of XAUR due to rules written in white paper. The ratio to the XAUR will never be lower than it is now, it can only be higher. That's why it pays to keep XAUR. You know exactly how much gold is actually worth. And the ratio of the coin is increasing due to rules written in white paper.
The relationship is changed every time a trensaction is performed in the XAUR. With each transaction 0.5 XAUR is destroyed, while the amount of gold remains the same. The relationship also changes if new gold is purchased and the new XAUR is issued in accordance with rules written in white paper.
If anyone wants to replace XAUR for gold, gold is handed over to the owner. Gold is withdrawn from stock, and XAUR is destroyed. In this case, the ratio remains the same.
This is one of those 99% of ICO's that were solely created to enrich its creators and will continue to exist only because of the hope of it's bagholders that it will increase in value and allow them to get some of their money back - however we know that it is not going to happen as the millions raised have already been divided between it's creators and spent on big houses and luxury cars.