Honestly, the process for the au/ nz schools isn't that difficult. I did it myself, and I'm sure most other people do too. It's also probably faster to do it yourself- one less set of hands for it all to go through.
The visa app process isn't that difficult, they lay it all out, and the people at the consulates are really helpful- all about answering stupid questions (heck, I sent them enough).
About the only advantage I can see to applying through australearn or whatever is if you can't come up with the first deposit yourself. They'll front the money, your loan goes thru them, and... I'm not sure where their money comes from- they probably charge processing fees or something.
Really tho? other than the deposit thing, all they do is tell you when to do stuff and do the international mailing. And you can easily do that yourself with a callender and some alerts on your computer.
j.