Generally, your advice is right, that only buying from official stores, and avoiding to purchase from third party websites as well as second-hand hardware wallets.
Individuals with the habit of buying fairly used items need to understand that not all items should be purchased as fairly used. When it comes to securing your investment, you should spare no resource in making sure that you do everything you can to ensure that your effort of investing does not go to waste.
This should not be a time to play the penny-wise, pound-foolish game, even if the vendor of this fairly used device is a close friend or even a family member.