US$ 60 for the display doesn't look that expensive. At US$ 190 total cost of manufacture for the 2, I would risk the wireless free forever subsidy seems to be a substantial part of the unit cost. Would it be a safe bet to estimate the display of the DX to be around US$ 120?
So, again, I would be happy with a DX that used wi-fi or my own GSM/3G instead of the US-only cellular network. And the bright side is that it could probably be sold for less than the current versions.
And Kindles are not that different from any other e-paper display device bundled with e-readers from many other sources.
The Kindle should be cheap to build