Middleman

I know people say that middlemen are people who watch and make sure everything goes well during a trade. What, though, exactly are they? And how would one perform in the following questions/scenarios.

2 scenarios in one question and another two questions.

Question one:

Scenario 1. You want to buy an account. With no middleman, the question of who goes first is there. With a middleman, what?

Scenario 2. You want to buy a couple of UBHPs, what role does he play?

Question two: What if you are selling?

Question three: Where can I get a middleman?

You want to buy an account. With no middleman, the question of who goes first is there? It is highly recommended that you use a MM. Don't go first unless they have tons of vouches and they can prove they are, who they say they are.

You want to buy a couple of UBHPs, what role does he play? The middleman's job is to (in example). If you're selling ubhp's, He holds the rings until the other person pays you the $ via the agreed format. If they 'buyer' does not send the money, The MM gives you the rings back and that's it, If the buyer, Pays you the money, You confirm it to the MM and the MM then gives the rings to the buyer. Vice versa.

What if you are selling? Same as previous q.

Where can I get a middleman? Official MM information is here: mpgh net/forum/showthread.php?t=572182 (Add a . after mpgh)