Why are people paying $668 for USED iP4s
when I can get them NEW from AT&T for $49
(plus the obligatory 2yr. yadayada plan?)
I don't 'get' the business of "unlocked"
...what am I missing here?
Unlocked means that you can use it with any carrier. If you bought it through ATT you used to be locked to using it only with ATT. When it's unlocked you could use it with any carrier. List of carriers.
Now about that GSM CDMA thing on that page, there are two different kinds of cellular networks, GSM and CDMA. ATT and T-Mobile use GSM for example, Verizon and Sprint use CDMA, CDMA doesn't exist overseas.
Not all iPhones are created equal in what bands they support. Up to and including the 4 they were either GSM or CDMA depending on your carrier. The 4s was the first dual band, GSM and CDMA, so unlocked it can be used with any carrier here or overseas. When going overseas you just buy a different sim card to make it work with a carrier there and not incur massive roaming charges.
The 5 has 3 versions. A US GSM version. An International GSM version for the different LTE (LTE=faster download) bands overseas. A CDMA/GSM model, but you have to go through Verizon or other CDMA carrier to get one. ATT only sells the GSM.
People want to buy phones outright rather than go for a contract because it's lots cheaper to buy the phone, and go with a prepaid month to month plan
. To get something comparable under contract it would be $112, the only difference is you'd have 3G download under contract, 2G prepaid plan, but you can add more for 10$ a G.
Under contract you're paying $1000-1500 or more extra for them to front you a phone for 2 years, and locked into them. The prepaid has more options for those that don't use it often. But you do have to come up with a few hundo to get started, as compared to best case .99 and sign the contract.
The unlocked and dual band are the biggest selling points.