I'm looking at getting one of my kids an iPhone on Xfinity Mobile. They have a promo right now where you buy the phone and then get a $250 mail-in rebate card. After taxes and rebate card, net price of an iPhone 7 32gb would be $235 and the net price of an iPhone 8 64gb would be $395. Is the 8 that much better to warrant the extra $160? There is also 2x the storage capacity which also helps in the 8 favor, but he only probably needs 18-20gb anyway. Thanks!