Question: If a seller agrees to sell me an account how would he post a middleman link for me to purchase it without someone else getting it first if I wasn't online at that moment?
Post in the listing: "I have completed payment for this account. The item is no longer available for purchase." That way nobody else will pay for it. Typically we remove the ability for someone to purchase it a 2nd time but if we don't and 2 people pay for it, we give it to the person who paid first.