In some ways the profit they make from postage is a good idea to make money for their company etc, but not the best public relations campaign.
Having said that, out of the dozen or more orders I have recieved from Marco's over the last 3 years, (and some very big orders), the postage has always been exactly what the package has printed on it and I havent been charged a handling fee.
BUT, if they send u one x screw in a packet, its $30. If they send u 12 things, which make up a small box, its $33. Maybe their minimum $30 postage is designed to make sure buy you more to fill the small box so u can feel better about the postage.
Marco's shld run Australia Post, it would be running at a huge profit in no time.