I purchased a full priced, unlocked iPhone 6+ from Apple this past February. I had heard for years that it made more sense to buy full price and go off contract with carriers because you could always resell iPhones for close to what you bought them for. Unfortunately, Gazelle, eBay and Craigslist seem to be pricing my phone from $500 to $600 when i paid $850 for it. I plan on buying the 6S or 6S+ next week, so I will really just be funding my upgrade. In addition, AT&T doesn't have discounted plans for off contract users. I may even just do AT&T Next.