Look for Deals & Lock In a Trade-in Price
Trade-in values will fluctuate throughout the month so the sooner you lock in a price the better. Locking in a trade doesn’t mean you need to go through with the sale.
Apple and its partners are also offering iPhone trade-in deals and you should investigate those before you lock-in a pre-order at full price.
Don't expect carriers to offer straight iPhone Xs price cuts for several weeks. If you want to save some cash on the iPhone Xs or iPhone Xs Max, you'll need to trade-in your current device.
If you want the maximum amount, it needs to be in great condition.