Wondering if you could pre-order a device a few days before upgrade is available, since the credit card isn't charged until a few days before the actual release date/shipping date. If so, would your upgrade be honored at time of processing to pay the reduced upgrade fee, even if you paid full price today to pre-order?
9/12: Order at full price
9/18: Upgrade becomes available
9/22: iPhone ships/credit card is charged at reduced/upgrade rate versus price shown when pre-order placed on 9/12
9/25: Receive iPhone
9/12: Order at full price
9/18: Upgrade becomes available
9/22: iPhone ships/credit card is charged at reduced/upgrade rate versus price shown when pre-order placed on 9/12
9/25: Receive iPhone