Apple Watch

You have to but a Cellular + GPS model Apple Watch.

If you purchased from Apple on or after 1-Nov-2021, you can return by 8-Jan-2022 for a full refund

Apple has a trade-in program.

There are 3rd parties that will but your used Apple Watch.

You can hand it down to a family member.

You can't upgrade a GPS watch to cellular,you have to have the cellular version of the watch as this has the Esim that uses your phones number to make calls and send texts.