I didn't bother clicking "But Now" since I know there are no AT&T iPhones available for pickup around Philly. But it's best not to click it in case you have it set to shipping and you want to pick up instead.How are people doing in store pickup with the express checkout option? When I click "buy now" it doesn't seem to give me an in store pickup option.
Best way is to add your iPhone and any accessories to your cart before turning on express checkout. When turning on express checkout, there are options to either ship, pick up, or to ask you every time you check out. You'll also get to assign shipping address and store for pick up.