Good point! The thing you have to take into consideration is some guy building in is garage has no overhead to worry about like a huge fab facility, laborers, payroll liabilities, utilities, huge government taxes, etc. So there is a difference. It's easy for him to make money when he doesn't have all the extra cost that a business in America has.
There are obviously pros and cons to purchasing from an individual or a company. You would hope that ordering from a company would come with better customer service and faster turn around, because they have the man power to do so.
However, once you get through the ordering/purchasing process and you have the rack on your vehicle, all that is left is quality and functionality of the rack. I believe that CBI turns out a quality product, but is it worth double what I can get from someone else? Everyone has to answer that question for themselves. My answer is no.
The truth of the matter is that the extra price you are paying is probably going to overhead/advertising/etc, not higher quality build materials or quality of the rack. You might get a warranty when ordering from a company, but really, how many things could actually go wrong with a roof rack?
Back to the actual R&D, My ceiling for a roof rack like this is $600 - I'd pay more for a ladder option. In my opinion, there should be multiple options and add on options (like the ladder, spare tire mount, etc)
I would probably prefer 1 piece construction, but wouldn't want to pay to have that monster shipped, so I would think a bolt together option would appeal more to the masses. I also think universal adapters and tie downs are a big plus since each person will probably use/modify it to their own needs.
Hope this helps