I think it is going to be too late for a 500GHs device in late Q4
Well they have said that the chips are 500 GH, not the devices. Maybe they'll throw 16 of them in a box and charge 7k for it? Don't really see how they will generate much in the way of orders otherwise.
People don't realize that multiple chips make up miners. They need to be at the magical number of 1th per $1000ish or less to be worthwhile against any competition and longevity as they seem to be hinting at.
that would be great but is it possible?
Probably not. Silicon wafer's aren't that cheap. Even in high volume we are talking $5K a piece. So there will always be a chip production cost. Unless you get a design which is significantly more efficient (GH/s per mm) at the same process (28nm) you are probably looking at more than that just for chip production cost. Of course that ignores the BOM, assembly, testing, defects, profit margin, and amortizing the NRE. I don't know how low chip companies can go but I think $1 per GH/s is like hoping gold will go below $300 an ounce (current minimal production cost).