Jesus H. Christ! $28 for a single merit? That's like the black market rate for a Suboxone strip, a similar crazy-ass markup (and no, I don't participate in either black market). I'm stunned.
Supply and demand. Don't be so surprised, people will sell their mother for merit 
What sort of loser would pay that amount of money
A loser with more money than brains or morals--and there are quite a few on bitcointalk from what I've seen.Many users don't see bigger picture, many users still believe that bounty campaigns are worthless and people are earning cents while truth is that many users are earning $10K+ monthly.
It's very unfair to those members who work very hard to get merit and these peole are just getting merits in an easy way.
Wadafak? Posting on forum isn't work.I'm pretty sure DT will negs trust both the seller and buyer and no more sig camp for them 
Just look at how many negative tagged members are participating in bounty campaigns. 
From what I see merits are mostly exchanged between users, you know, scratch my back and I will scratch yours. They can't exchange merits with legendary members because legendary doesn't really need merit, so if they want merits from legendary they can either begg for it or buy it. Now, who is stupid enough to risk negative tag on legendary account for few bucks?
So, low supply, high demand and high risk = 28$ worth merit. Ok, I don't know whether that number from OP is accurate, but nothing surprise me here.