First off
1. Check for repuation or vouches! We DO have a vouch forum and there are plenty to check for the seller/buyer!
2. Ask for the User-name of the Account before buying to check if it is VAILD
3. Check for alot of posts / Badages usually if they are Moderator / Middle Man (MM) or Admin Your good to go(USUALLY)
4. If they have recent scam history but aren't banned use a middle man! or in the case if they have 5 - 10 posts and signed up yesterday and they're first post was in the account section USE A MIDDLE MAN(MM)
5. If they are trusted and super active (500++posts) and If they ask to go first, and your a lower rank YOU need to go first unless they are nice enough to let you go second!