...possibly because selling them is illegal?!?!
Hello and welcome, first post I see, you're wrong, but thank you for butting in anyway.
There are a few different types of key, the Full version, which we can, and do, sell, and the OEM one, which is licenced from Microsoft by the PC manufacturer, and so can only be sold with the machine, selling it in any other way is in breach of the Microsoft terms of licence.
We were selling the plastic bases from the laptops we were breaking down, they still had the COA keys on them and it was this that Microsoft objected to, they either wanted them removing or for a greater amount of the original laptop to be included in any Sale
where they might be.
Welcome to the machine, sit back, relax, enjoy.