Windows 10: Is this StackSocial Windows 10 Pro license offer legitimate purchase option?

Is this legitimate, or buyer beware ?https://www.stacksocial.com/sales/microsoft-windows-11-pro-6

:)

 

Which win11 pro upgrade is legitimate?

I see plenty of sites selling win11 pro upgrade for cheap, like $25 (e.g. stacksocial). But I think they are OEM licenses.

bestbuy sell them for $100 each.

How can you tell which one is legitimate? What is the cheapest, legitimate one selling for? And why don't Microsoft shut down the illegitimate ones?

 

Can't install Office as it's asking for a key number. I have a license code from Stacksocial (Marketplace/Retailer), where I purchased Office Pro 2021from this week on Monday.

Can't install Office as it's asking for a key number. I have a license code from Stacksocial (Marketplace/Retailer), where I purchased Office Pro 2021 from this week on Monday. I need to know how to proceed ...

 

I purchased Microsoft Office Professional 2021 for Windows: Lifetime License from StackSocial. But Microsoft OneDrive is saying I still have a full storage.

I purchased Microsoft Office Professional 2021 for Windows: Lifetime License from StackSocial. But Microsoft OneDrive is saying I still have a full storage. Why?