Doctors. Lawyers. and Car Dealers. Having a certificate does show you have taken the time and resources to obtain it and therefore shows something. However, as we all know, it does not prove you know what you are doing or that you are reliable. It's speaks to the core of human kind. Each entity should be judged on their demonstrated ability to to the right thing. There are many good and bad from both the ilks of curbsters and dealers. Neither should be evaluated by the fact they are one or the other, they should be judged by their deeds. Go through the Kiiji classifieds and see how many 'licensed dealers' are advertising there alongside the curbers. Many of the dealers that are held in high regard in this forum started out from personal roots.
I've recently seen an example of a dealer selling a pristine example of an HDJ81 with a camper on the back of it for $39,000.00. I watched that vehicle go at the USS auction in Japan on Dec 27th for 1,480,000 Yen ($14,000.00 USD). When you can almost double your money as a dealer, it would seem the process of natural selection will dictate most worthwhile curbers will evolve to become dealers withal.