iPhone time

I've had my current iPhone ( a version 4) for almost 3 and a half years now, and it's showing signs of wear, tear and slowdown. It's time to upgrade, and I'm looking at an iPhone 5s. I've dallied with the idea of moving to Android, but I'm a die hard iPhone man at heart, and it complements my iPad Mini and Macbook Pro. I've got a birthday coming up to, so nows the best opportunity to get one. I don't expect one for my birthday, let's get that straight - they're a LOT of money, but a contribution in lieu of a gift wrapped present would be ideal..... Ooohh, shiny...