I think quite a few of us do the "buy it outright" thing, and then sell when we're ready to upgrade and do it all over again. I've done this for a few years, but before the iPhone 6, I've been on Android, and I've only had one "top-tier" Android phone (the GS3). I'm wondering, financially speaking, what does one typical lose/spend doing this every year vs every two years. Upgrading every 2 years, you obviously are spending less, but you're also losing value on your current phone. Common sense / logic says you spend less money doing this every other year, but I'm wondering what the typical difference actually is. My guess is that you lose more value in year 1 than you do in year 2, but maybe the depreciation is more linear than I think it is. Take this years 64GB iPhone 6 for example. It costs roughly $800 after tax. In one years time, the cost will typically drop by X. In two years time, it'll drop by X+Y. We'll assume the price of a new 64GB iPhone will be the same for years 1 and 2. Anyone have any educated suggestions for X and Y based on past experience?