iPhones in general are much better in build quality then the average competing Android phones. The highest end of Android may be better but certainly not the average. Fair or not, most cell providers give the customers access to inferior Android phones when comparing against Apple at the same price to the consumer. For the consumer to get one of the better Android phones they need to pay more money.
Finally iPhones hold their value (for resale) much better.
http://appleinsider.com/articles/13/11/05/iphone-retains-128-more-value-over-time-than-apples-competition-ipad-worth-67-more
Despite all of these advantages I may end up going Android.
iphones hold resale value better because they are not discounted as much as android based phones.
ie: if you bought your galaxy s4 for $50, then the resale value will be lower than an iphone which you purchased for the retail amount of $199.
iphones holding $128 more value makes sense, because if you are paying $50 for your gs4 with a 2 year contract, and $199 for an iphone with a 2 year contract... the resale value would be the same if you sold the gs4 for $300 vs. $450 for the iphone.
That's not what the numbers say. The numbers say that any given amount of money spent on a iPhone keeps its value as a percentage much better.
To illustrate that point...
I pay $299 for three phones in a row (4, 4s, 5) and sell them for MORE then I paid for them. In most cases it was $350. Sure AT&T subsidies the purchase price, but in the end the consumer wins on resale value. And yes, I know we pay for or (sorta) monthly.