No you cannot. This is considered proxy selling and is against the rules. If your friend wishes to sell something in the premium seller's section he must do so himself. Any attempt to get around this rule usually results in a repfuck and closing of accounts.
Can I sell for other members?
Members are not allowed to sell for another member here. Those who are ban evaders, negative reps or not upgraded should not be allowed to sell in our marketplace by proxy of another member.
Source: http://hackforums.net/misc.php?action=help&hid=35
Can I sell for other members?
Members are not allowed to sell for another member here. Those who are ban evaders, negative reps or not upgraded should not be allowed to sell in our marketplace by proxy of another member.
Source: http://hackforums.net/misc.php?action=help&hid=35