Make sure you are buying a new phone when you ask for a new phone. Not that used phones are bad, some are actually reconditioned to like new, and sold with a full warranty and all. But it never hurts to ask now does it. If you do buy used equipment, find out if the dealer has a warranty with it. Some used phones do have either an in-house warranty or limited warranty.
Phones come and go like service plans.
What's hot this month may not even be made next month. So make sure that the phone you are buying can still be repaired, can still have accessories bought for it, and most of all, has not been discontinued within the past 2 years. Keep in mind though that a discontinued phone isn't a bad thing, just make sure you know. If anything, it will show that you have an honest agent. This isn't necessarily bad, but you should be informed.