Trade with caution. He wanted me to go first because he claimed to be trusted (he has free vouches from free service).
At first I had an MM, he said he found someone cheaper. A few hours later he wanted to buy 50M, my MM was offline and I said I'd go with the trade but he'd have to pay for an OMM. He said he was trusted and I took a look at his vouches, I showed him mine and said I did more than double that. Then he asked if I was going first, I replied with a "No, I told you a while ago we'd use my MM and now he's offline" and he said "Then keep your shit! Peace"
Very impolite and not a guy I personally would trade with.