Report the unsolicited message to the moderators. I believe that user could be attempting to send that similar message to other users. And the let us know who is that sending such messages. DT members still tag/flag account sellers as they can not be trusted.
You already tagged the account and the remaining thing you can do is reporting it to forum moderator. You are hesitating to do report, perhaps it is a newbie account, but why don't report it?
Moderator will handle your report and ban or nuke that newbie account.
Moderator can not do anything with the person. The account can not be banned. The main really for account ban on this forum is plagiarism or after warning from something like spamming.
It can be banned for sending unsolicited messages.