Staff cannot do anything about this, so technically it is allowed, but HIGHLY discouraged
We've given out so many warnings in the past about why accepting/giving out accounts is a bad idea, and we try to make it as clear as possible that anyone who participates in any of this is taking their own risk. Why someone would want to buy an account is beyond me (since with patience anyone can get one for no money at all), but if people choose to do so it's on them and them alone
Hope this answers your question