How is my build and what should I charge for it?

I think that considering what your computer is capable of, that you could easily charge over $18,000. This is for graphic design, 3D rendering and video editing, I presume. I recommend that you add in a sound card anyway. Doesn't have to be super top notch, but a sound card will greatly benefit anyone who needs to hear sound on the workstation, especially people who are doing sound editing and video editing.