I personally don't think that mexxer-2 IS Quickseller, but it's very possible that mexxer-2 is a bought account. If you look at the beginning posts of him, he is selling accounts and placing sports bets + posting in off-topic a bit (which is a very common trait of accounts that are farmed to be sold - they sell accounts that are ripe for the selling and build the account up at the same time).
EDIT: Here's a list of posts that he did, consecutively.
...and 4 posts later...
Perhaps he's lookin' forward to being administered 314 lashes with a wet noodle for punishment?
Why a wet noodle?
Why is your name so rude?
Why do you care?
...one post later...
Strange that he's cracking down on spammers (especially in Off-Topic) if he *supposedly* had a history of posting in off-topic like a spammer...?
EDIT2: https://archive.is/lkUHq
EDIT: Here's a list of posts that he did, consecutively.
from friend of course 
Total time logged in: 2 days, 15 hours and 28 minutes.
"Why would bitcoin be about math?"
Why didn't you quote last answer?counter strike go 
I have 34 messages 
Green ice tea
...and 4 posts later...
"Why would bitcoin be about math?"
Why didn't you quote last answer?Perhaps he's lookin' forward to being administered 314 lashes with a wet noodle for punishment?
Why a wet noodle?
...one post later...
Black tea
Strange that he's cracking down on spammers (especially in Off-Topic) if he *supposedly* had a history of posting in off-topic like a spammer...?
EDIT2: https://archive.is/lkUHq