Well, at least for the PC market and in this corner of the world, games can be purchased at discount after a reasonable period of time. Otherwise - well, except by pirating - I couldn't afford the hobby anymore. As a student with about 50? to spare each month, you think thrice if you really want to blow it for a game at release, risking you might end up with some ridiculousy short, bug riddled or otherwise unsatisfying game.
And so the bargain bin, ebay, sales at steam and impulse, gog.com together with mods and the special el cheapo publishers here which sell games a year or two after release for 10? at retail is the real alternative for me to give up gaming or becoming a permanent resident at the pirate bay. And except ebay, I'm still giving good money to the developers/publishers so they are borderline lunatics to not embrace this but driving the more honest people away from the hobby and less honest people to piracy.
And the Australian prices are a blatant ripoff, there is no need to suggercoat that. The prices in Europe are mildly higher then in the US but this is somewhat justified by localization to German, French, Spanish and so on. In Australia they sell the exact same game, in the exact same box for the double amount of money.