(This seems the closest fit forum, admin please feel free to move it around if there's a better one.)
The requirement: simple/cheap method to near realtime track a parcel travelling between main centres, or at least ping it to report current location. Budget below $50 if possible.
Best option: small, long battery life, dedicated unit that'd work on 3G/4G network. Aliexpress etc all seem to want to track a car/motorbike and powered.
Possible - 2nd hand cheap android phone and an app? The concern with that one is a courier parcel being flown with an active phone may not be looked upon ...shall we say favourably by the transport network. Yes, I know a SMS option would also be active but that could be managed.
And, as always, just asking for a friend.