That harly's stuff isn't 100% carnauba wax, as it would be solid if it was and not a wax fit for your car.
Dodo juice make a nice paper weight which is 100% carnauba wax.
What it usually means is out of the wax content that is used it is all carnauba wax, and not a blend of waxes.
However what it doesn't say, is how much of the total tin is wax. That tin could only have 1g of wax in the tin, but be 100% carnauba wax
A blend of waxes is usually good, as most manufacturers seem to think so and give different charactristics of the waxes.
You pays your monies for what you get. Definative waxes are getting good reviews over on DW, and they range from £50, for wheels up to a £2k.
Agreed some punch well above their price point, like Bouncers or Autobrites ranges of waxes and some are just hyped with a nice bit of marketing, but they must sell some, otherwise they won't make any.