Why buy an account when you can easily create an account? If you are buying an already ranked account, then probably you just want to jump into the signature campaign, or you have other motives for it, you don’t really care about the forum, and what you care about is just what you will earn from the forum, or maybe you want to use the account for illegal activity.
 
I am not saying it’s bad to participate in signature campaigns, but if you want to do that, then make contributions to the forum and build your account yourself. You don’t have to buy an account, if anyone can buy a forum account, then I will say the person isn’t having a good intention towards the forum, because most people who purchase accounts do use them for either scams or just to make money from the forum.