For my international phones (I have one permanent for SA and another for pop-in SIMs elsewhere), I generally rely on buying refurb'ed phones from APPL/AMZN to "upgrade" every once and a while. So I'm not trading in the older models of those phones when I "upgrade." I actually travel with about 1-3 of the older model iPhones that have been replaced by the newer version/refurb'ed models. If one of my "working" phones gets nicked, I have backup(s). Touch wood, never needed to go with this plan.

Often, at the end of trip (particularly in SA), I leave 1 or 2 behind with family members' staff. It's an upgrade for them and they - at least outwardly - appreciate it.