Like many other smart phones, iPhones - particularly the more recent releases - do have the potential to be very expensive indeed. However, there are a range of options that could mean it is possible to buy a cheaper one that still works just as well. Options include buying an older but cheaper model, such as the 3 or 3G, or picking one up from a newer range that may be cheaper due to design defects.
Many people who are mobile phone enthusiasts will get rid of their old model the moment a newer one comes out. For example, with the advent of the iPhone 5S, many people in their hurry to get one sold their iPhone 5 models for a much cheaper than asking price. This is a good way of getting something that is still a top notch quality product without having to pay the full price when it is first available for sale. Similarly, others who like their phones looking 'box fresh' will sell theirs cheaply if a tiny scratch or chip occurs in the screen. Largely this damage will not affect the phone's performance or noticeably damage the appearance.
iPhones also come with a variety of accessories, from charging appliances to speakers and headphones with which to play music. Most charging appliances work across the entire iPhone range, although it is worth noting that iPhone 5 models - including the 5S - have a different size charging port than previous versions such as the 3, 4 and 4S.