iPhone

I've been looking out for an iPhone, but, here in Europe, lately all you see are the "clones" looking similar to the real deal. Most people tell me that in the US iPhones are real cheap, which by the input I have is not true. What is an iPhone worth in the US? Lets place a 16GB as the wanted unit. I know there is a huge diference between units on a contract and units without contract. What about used units?

Regards