rank up ur account first then join a signature camp and keep posting to earn, very simple 
it might be much easier if he would decide to buy the accounts instead of leveling up his new one though its my thoughts onlyI don't suggest buying accounts. Raising an account will always be better. And you gain knowledge from your time on the forums.
If you use a bought account a lot of them are crap farmed posts. This means not all people will want you if you buy an account and have bad post quality. Yes some will get away with buying, but it really should not be supported as far as for signature campaigns.
Human greed as always and we can't stop that. They want to claim more and never get satisfied. Everyone can having more than 1 account but there will be some risk for it so think wisely
We cannot stop greed. But the funny part is likely some of them will buy accounts full of "one liners" like thanks or my favorite is offtopics like favorite drink. Gee every day they say what they drink.
These accounts will apply to a "good" sig campaign and be turned down. Yes a few will make it through but most of the farmed accounts really are quite crappy. I wish everyone would enjoy the forums and not try to fast track. But I do see why one would be wanting to fast track, I highly suggest them thinking twice before doing it.
Fast track as in buying an account. It fast tracks them to a certain level, but as you can see from my posts I personally am very against this for just getting on a sig campaign.
I think you should get an account and raise it from newbie to whatever. But I could be old fashioned.
I am not angry. It is part of the forums they allow sales of accounts. So I cant really be angry.
I just think someone jumps to your example of senior rank they missed out of a lot of knowledge and time of forums most would be expected to have at that rank. I feel they are missing the point of the forum, but that is just my feelings.
Funny thing is a lot of these accounts have horrible post history. The fact is a lot are "farmed" and some even "botted" read meta to learn about the accounts that used bot it's amazing the lengths some of these account farmers do. But if you have a horrible post history you will not be allowed in a lot of the better signature campaigns. So someone might be wasting money on that account you speak of.