Are those figures just from USA? As article doesn't mentioned it I assumed they are worldwide which makes your observations misleading. IPhone is available to "unlocked" purchase in many countries (and it is really expensive phone then[1]) and even if you buy it with contract it doesn't get that cheap everywhere. So in many countries, the premium is very visible.

1. http://www.flickr.com/photos/choreographics/4836719813/sizes...