That product was manufactured some years ago by XS Scuba as a custom run for a US Government military contract, the black color Mil-Spec PVD coating engineered to remove the shiny reflective surfaces. That date code I think is 2010 year and 20th week. (They later propagated that PVD finish to a stand alone valve in their sport valve line. Why not , Uncle Sam paid for the development.) The quantity needed was relatively small single run and to recover the setup costs the per item price was ridiculously high. As I recall we were asked by XS as a favor to list it on our website for a little while as a 'special order' to establish the retail price. It was only in one or two issues of the XS price list for some reason (possibly related to govt purchasing rules) and in our records as having a zero cost and a retail price of $750 per manifold which of course doesn't make sense. Notice it has a green 40% Nitrox information card (instead a pink Air Only card) yet also 3300 psi PRD, which would be a 5500 psi release pressure on an aluminum 100 cylinder which the DOT says cannot be filled with nitrox higher than 3000 psi.
Your tax dollars at work, it's certainly a 'collectors item' now. Mark Gibello at XS Scuba might recall more about the history of how that product came to be.