Few questions
1) What's the benefit of buying now instead of last day of the RICO?
After minting, Xaurum ratio will increase, this means the base value of each xaurum will increase, and will consequently be more costly to create. Nobody can know how much more the cost will increase in advance, yet it is certain to increase, as it depends on the number of funds collected and number of new xaurum coined. After the first mint, a new minting price will be published.
2) Is supply limited or not?
The supply is not limited, because for Xaurum, inflation increases the value.
3) Is this RICO like digixDAO's ? (when they reached 5.5 M they went "out of stock")
The unlimited supply already answers this, but we should delineate some additional differences from digixDAO, that only collects fees from their digital assets. Xaurum is not a representation of gold, but a form of money that uses gold. It also collects fees, but this is really the lowest form of income of the Xaurum commonwealth, until a significant increase in userbase and volume. The main part of the gold reserve increase comes from Xaurum coinage, that at the same time benefits all of the users and the minter/miner.