I've also wondered about that. I often see new iPods going for msrp or over it. And it always annoys me because people are paying for it what it costs in the store PLUS shipping when apple.com offers FREE shipping.
But I guess you have to take into account that the buyer isn't paying tax. So maybe they save like $20. I'd still rather buy it straight from Apple.
I guess you have to live abroad in order to understand, cause for us there´s zero to none access to iphones if you´re not a US citizen. So it´s either uber expensive or nothing.