Buying and Selling of merits is a shortcut to get a negative feedback and hopefully account ban. There're several threads including mine, who're taking pains to review posts and give you merit, no need to buy and sell.

Report people like : give me merits I'll give you back.
I'll sell you merits for X amount.

Don't make this stupid mistake of buying and selling, like the eye that sees it all, everyone is watching. #idontdoshadydeals