Prices vary according to the quality of the account, its ability to enter signature campaigns and the points of trust in it, but it is a risk that is not worth it, especially if your motive is purely economic (scamming people or participating in signature campaigns)
By the way, in posting, the differences between ranks are almost non-existent.
Selling accounts is now stupid - although allowed officially, seller, buyer, the account to be sold will be tagged when caught. And it's a good step forward, since the reasons for such a deal can be at least shady, if not plain scam.
Plus now the merit system makes leveling up difficult for spammers, so the way the worth was calculated in 2013-2015 (I don't know the exact years) is different from what it would mean now.
Sometimes, let us assume, for example, a high-ranking member who has been banned for any reason or wants to increase his profits by having more than one account. Instead of waiting 8 months, he will buy an account and will not face a problem in ranking.
Also, spammers know that it is impossible for them to rank-up, so buying an account and participating in bounty campaigns is a good option.