if u consider the 3G network and actually use it frequetly to browse the web, $500 for the device is actually a bargain. your cellular 3G data plan is $30+ per month. include the tax and that's $400 per yr right there! but of course, the majority of the people who buy the kindle dx probably have 3G phones, like myself.
it'll save u money on news paper subscriptions also if u use it to surf the web, which I plan to do when I'm not in the subway.