UBS said the factory cost of the 64GB OLED iPhone will be $70 to $90 higher than the iPhone 7 Plus model with a sale price of between $850 and $900. The higher cost could weigh on Apple's gross margin which UBS said is likely to decline to 38.5 percent in the fiscal 2018 year, from its estimate of 38.7 percent for the current fiscal year. But the 64GB...