Yes, it is. Do you think / assume / have evidence that there is also payment-based merit sending? Like users paying others for earning merits.
It has happened. But there's this:
If you have to pay $20 per merit plus a risk of getting red trust, then that's a situation that doesn't concern me at all. I'm not going to lose sleep over people going to ridiculous lengths to buy merit, since only a small number of people will be willing and able to do that.
As long as merit sales are a black market, I'm happy, since that makes it far more difficult and expensive to buy merit. If that's the case, then the small volume of black-market merit trades don't themselves bother me much, and I think that it does more harm than good to get too witch-hunty about it.
If I could (for instance) buy 10,000 merits and be a shitposter, would anyone look at me as a serious user?
I think it's more like buying a single Merit to reach Jr. Member and continue bounty spamming.