Safe to buy second hand mac mini?

Beware of purchasing any used Mac from a source with unknown dependability.

Having said that, it sounds like this will be the purchase of a brand new Mac mini, so some potential problems with taking ownership and setting up the Mac would be eliminated.

Regarding the question of stopping payments... no, Apple will not come and repossess your Mac, but whomever's card was charged may face a hit to their creditworthiness.

Using the warranty may require that you have a valid proof of purchase, a valid receipt that details the Mac s/n and the date of purchase. This person should at least send you a copy of that with your new Mac mini.

FYI: Apple - One Year Limited Warranty - Worldwide

Edit – Reading your post again it seems this may in fact be a used Mac mini that you are buying? If that is the case, then my first reaction definitely stands. You will need to ensure that the previous owner followed this guidance prior to handing the computer over: What to do before you sell, give away, or trade in your Mac - Apple Support

Their failure to do the above is certain to cause problems with you setting up the machine.

You're welcome.

It sounds to me like the email that she is sending would likely be enough.

After all, if there is nothing else, there is nothing else. Apple can't require a retailer to include a s/n on a purchase receipt. Or can they? 😉

Anyway, enjoy your new Mac mini, my friend.

And don't hesitate to post here again if you feel the need.

Since the M2 mini is not available in your country, I would question if you could get software/security updates for a Mac purchased in the U.S. or even if an Apple warranty is valid in a country where Apple does not sell the device.

Your country may impose an import duty on the Mac that you are responsible for before they will release it from customs. And if your country is one that U.S. export regulations has banned, the Mac may not make it out of the U.S.