What to look for when buying a Microsoft Office 2019 Home and Student?

I have a new notebook with Windows 10 Home installed without Word, Excel, PowerPoint license. Now I have (unfortunately) buy Microsoft Office 2019 Home and Student do so. At Saturn, it costs 149.90 euro (1User, full version). Now I googled and came across many offers from 19 euro (1User, full version). There are sooo big price differences (something is lazy, right?). What to look for when buying a Microsoft Office 2019 Home and Student at such large price differences?

(It is also possible to work only with OpenOffice (free), but I receive emails with Microsoft Word and Excel attachments, so buy it)

I recently bought that complete package of Office 2019 for a good 60 euro on Amazon. The key was sent to me with instructions within 24 hours and everything worked out great. Would pay attention to the recessions, if the are good, everything is usually OK.

-Access
-PowerPoint
-Excel
-word
-Outlook
-Publisher
and skype buisiness were there

Get at MMOGA for 30 euro

https://www.mmoga.de/Software/Office/Microsoft-Office-2019-Professional-Plus-1-User.html

Have brought there a while ago, the 2016 version, gave / gives no problems

Look here: https://www.rakuten.de/produkt/microsoft-office-2019-professional-plus-2467807470 This is just the product key. You will receive it after payment by e-mail. Then you go to https://setup.office.com/ After activation, the license is permanently stored in your Microsoft account. If you have to reinstall, just log in again with the Microsoft account and you can download it again and it will be automatically activated again. This license is permanent.

This low price is an OEM version. OEM versions are full versions that came with a computer. A court ruling from the year 2000 has decided that you can also buy and sell OEM versions separately.

We have internet.
12 hours.
Mario.