I initially thought you meant discrimination between rich and poor, but "grab money from everyone" still discriminates against people that can't afford the visa/passport.

Citizens have rights and eligibilities that non-citizens don't. That's not discrimination that needs to be addressed; it's national sovereignty. Non-citizens aren't eligible for HECS, aren't eligible to vote, aren't eligible for a passport, and aren't eligible for federal jobs. Non-citizens aren't eligible for these because they are not Australian.

Live here and choose to become an Australian, or live here and choose to not become an Australian. Choose the latter and you'll need a visa.

For the record; I think the Returning Resident visa fee is exorbitant. I also think the suggestion that Australians should pay more so it's fair for non-Australians is ridiculous.