Here we go again.... 30% is not highway robbery. 30% margin is low for a distributor in the software world. Ask MacMall to carry your product and see what it costs. Apple's 30% will look very attractive quickly.
I am sorry, are we talking about apples or oranges?
MacMall generally deals with physical products, which involve costs for transportation, storage and shipping, among others. Plus, the products they sell are not part of a closed ecosystem, which supports sales of some MacMall hardware responsible for the majority of MacMall's revenue.
Apple has a monopoly, for practical purposes, and this is the only reason it can get away with 30%.