You Can Buy AppleCare Later
You'll also likely be tempted by AppleCare.
If you're unfamiliar with AppleCare, it's Apple’s extended warranty service. Many of you will eventually want to get it, but you don't have to make that decision during the pre-order process.
If you don't have time to research the service ahead of pre-orders, you'll want to put in the time after you buy your iPhone Xs.
If you aren't familiar with the service and its benefits, hold off until you've been able to weigh the pros and cons.
You should have a 30 day window to buy AppleCare which means you'll be able to buy your iPhone Xs and pickup Apple Care later if you want it.