What’s morally dubious about this?
For Windows 10 you have to obtain Enterprise LTSC license. Those come only via volume-deals and are not officially available for us mere mortals. On the other hand, in EU reselling licenses is explicitly allowed (no matter what EULA tells you) and there are tons of dirt-cheap second-hand LTSC licenses. Again - one can see this as either outright stealing or exercising your consumer rights.
No idea how that applies to US laws.