Software is probably volume licensed for enterprise use. No one here as a single home user is going to make up their mind to buy something which they can get for a few $ for a single user license.
Also as you said earlier,
"most businesses have regulations and standards in place, so breaking them isn't really an option".
You're right but I feel this is something that as a business you have to absorb the cost as an operation expense. You can't offload this cost on just one buyer.
Also perhaps you can provide more details about the Windows and the Office license. What's really special about it?
For Windows, SKU? Channel (Retail/VL)? Activation count if VL?
For Office, same as above + duration (Volume license is perpetual and the costliest)?
You probably know how but if not then you can use this info:
https://techenclave.com/threads/ms-keys-thread-issues.209023/post-2399510
And as a note, if these are indeed volume license keys then you can't sell it legally as you will violate the license terms and it would be illegal. Volume MAK keys are a part of Microsoft's Volume license agreement and they come with a VLSC account which I'm sure you won't sell if you possess.