The reason there's so many for sale is because people are finding out that the Wyred4sound 10th anniversary DAC for $4,500 is much better than the bricasti, I was on their site and they're also out of the silver version only the black version left so people are definitely snapping them up.
Hmmm, could it be the '10th anniversary' DACs are out of stock because they were released in the late 2017 timeframe? :)