it easy high rank acount have more credibility so they are more trusted ex: two sellers in this forum one newbie and one legendary even if the legendary sell in higher price people will buy from him cause he is more trustable . you have less chances to be scammed by a legendary acount . that why high lvl acount are more precious abd even if it illegal some people sell or buy them . 
Buying and selling accounts is not illegal (not against the forum rules). It is frowned upon, and, if caught, the buyer AND seller will probably receive negative trust from DT... However, the buyer and seller will not be banned, since account sales are not forbidden...
https://bitcointalk.org/index.php?topic=703657.0#post_rules
read rule 18
Don't get me wrong: i'm not an advocate of account sales... I'm just saying that the claim that account sales are illegal is false... They are frowned upon, discouraged, distrusted,... but not illegal.
OP: i think you've gotten your answer in the first 2 posts in your thread, in my opinion the other answers were just rehashing the first two answers... Please close this topic to avoid clutter.