Just noticed that the Arduino Due together with all the previously discontinued shields are now available on the Arduino.cc products page oncemore. From the image it looks like Arduino.org's Due: https://www.arduino.cc/en/Main/ArduinoBoardDue.
Listed yes, but the “Shop now” button is missing, you cannot buy Due from arduino.cc:
But there are many Due suppliers on aliexpress:
Oops, Due did cost 12$ on aliexpress for a year at least, now all have raised to 14.50$ or higher.