Alright, I got the point. The point of making a common account is to have an account with shared credentials. And there is no intention of buying the account rather making an account that grows organically under the ambit of forum rules.
Just FYI in case you didn't know, none of the people who answered your question are staff, nor am I. I'm not sure if staff will stop by to answer it, but they do tend to do just that eventually. It would probably be good if one of them answered this question.
My own non-staff opinion is that it's not a problem at all. Even having multiple accounts here is allowed, and I have never seen a rule against multiple individuals sharing the same one--but I'd say you're doing the right thing by asking first. That's more than most bitcointalkers would do.
What isn't kosher is entering one account into multiple campaigns/bounties, or having multiple accounts using the same ETH or btc address, but it doesn't sound like that's your intention. That's not even a forum rule anyway, but it's something the community enforces. Good luck.