There are several U.S dealers of Vulcan products, one of which is a sponsor on this site. Just for informational reference, I started conversing with Addictive RC about frames and the requirements I had for my build. We spent a few hours over the course of several phone calls and e-mails, with John presenting various frame and equipment options for me to choose from. Ultimately I chose a Vulcan prototype 1200mm X-folder for a multitude of reasons. Price was not one of them because low prices and high quality are not often synonymous with each other. However, low prices, low quality, poor service, and long delivery times often are. Only one of the Vulcan 1200mm frames had been made to date and it was being used as an experiment in the U.K. for flight testing, so everything had to be made from scratch. The time span from date of order to the date of delivery was less than two weeks. Spare parts are only a phone call away, and that alone is "gold" for the multirotor vendor list. BTW, the frame is quite solid and provides a plethora of options for equipment choices.
I called and e-mailed a lot of dealers with only a few replies when I decided to start a custom build. Most of the "big names" never returned a call or e-mail, with one sending back an e-mail suggesting I contact their sales e-mail account instead of their listed "contact us" address. To date I've only come across five multirotor companies in the U.S. that I know I can depend on. I'll honor them with their names and hope others can add to the list. Addictive RC, 3D Robotics, ATI, Ready Made RC, X-Aircraft. I've had extremely pleasurable business experiences with Heli Video Pros in Canada as well.
Choose wisely. It's not just the money involved with a build that's at stake. Your reputation and/or future business opportunities will be on the line as well.