On May 20, 2017, another Apple-1 will hit the auction block. MacRumors reports that it will include "the original manual and documentation, the receipt for the motherboard and cassette recorder, and even a record of telephone conversations with Steve Jobs and Wozniak." It appears to be Apple-1 #14, as detailed in Mike Willegal’s Apple-1 Registry.
This is not the first time an Apple-1 has been sold by German auction house Breker: they sold one in November 2012 for $640,000, and another in May 2013 for $671,400. Expect this one to fetch a similarly high price.