Im thinking about being an account off of someone on the site. what do i need to check before buying it?

Before buying an account.

1. Check their reputation

Rep is very important when purchasing an account because they might RECOVER the account.

 

2. Past Marks

Although marks don't mean much on the account, it is a good indication that the account was once botted on.

 

3. Check

Check if the account has been sold before, if it has then that means the account is MOST LIKELY going to be recovered back again.

 

Other then that, best of luck buying an account.

I would read this and ensure they have filled in all the relevant parts - 

    1. Pictures of the account stats

    2. Pictures of the login details

    3. Pictures of the total wealth (if there is any)

    4. Pictures of the quests completed

    5. The price you will be starting bids at

    6. The A/W (Auto-win) for your account

    7. The methods of payment you are accepting

    8. Your trading conditions

    9. Account status

   10. Original/previous owners AND Original Email Address

 

+ I think it is best that you ensure they are the original owner, and that they will switch the email over to yours while providing creation IP + previous passwords so in case there ever is a recovery attempt you at least have some sort of a chance of getting it back.

Check if the seller is orig creator, if is willing to give you orig email, check stats, quests, blackmarks, items, anything valuable, anything that is associated to the account really.

i only buy from original owners that are known well and have a lot of rep.  very unlikely to be recovered

Basically what Novak said. Only buy from people who have high feedback (less risk of being scammed). Make sure the account is originally owned with the original email.