I personally don't have the time to live on Bitcointalk.org. I work 50+ hours a week and login to bitcointalk.org about twice a day to sale misc goods. Now is this fair to me, or others like me, that we can't rank up because of this? Again, opinions are like assholes, everyone has one. And I'm fairly sure you know mine. Point is, if Theymos can sell whitelist to be able to post more on Bitcointalk, then selling Merit Rank-ups should be no different.
Most of the people who are not here for signature campaigns need not bother about merits at all. The members who are not able to get merits and are thus not able to participate in bounties are the ones who are calling merit system a failure. Since, you primary purpose is to sell accounts here, why do you want a higher rank. You have already got sufficient relaxation in PMs and posting frequency as per your current rank. If you are providing good services or products and clients are happy, they will give positive trust to you and it will make your profile look more credible even without merits.