Other enchantments have "At the beginning of your upkeep, sacrifice this enchantment unless you pay {2}."
If two or more Aura Fluxes are on the battlefield, they will give the text to each other. And they will cause each other enchantment to have two triggered abilities for which the player would have to pay.
This card adds a triggered ability to all other enchantments.
You choose whether to pay {2} or not on resolution. If not, then you sacrifice the enchantment.