The antiques business is simple today
1. You have power if you can find a billioniare to spend 3m a year with you. You get this if you can listen and feel the collectors heart. You have to have spectacular knowledge but more than that you have to be able to listen to what is being asked for.
2. Or if you can figure out how to buy cheaply LEGALLY. This simply takes a great deal of work and thought. There are auction houses, appraisers, librarians, museum curators, collectors, historians, antique shows, e bay, abe, alibris, biblio, first dibs, artnet, book fairs and even other dealers that are possible sources.
Without success in one of the two, you are doomed to being a slug in this business.