MM, the Oryx white is more likely a crystal based paint, hence the cost, and probably would have a better shimmer than Glacier white (Audi). VW only list it as a special paint, but for £900 odd, it won't be just a pearl base.
The RS4 has Prism Silver, crystal effect and Panther Black, crystal effect which cost £865.
As you know Audi extra's are over the top, but this paint for a larger estate car seems even reasonable.