All I can guess is possibly $250. There were 3 options FiiO gave. The cheapest one gave the best sound quality but you can not charge while using, the second option was a bit below the first but you can charge, third option gave you some really good battery and charging apparatus, the lowest tier of the three in sound but also the most expensive. They put a poll up on FB AND on Head Fi (awesome right?) and the second option for the mix was chosen. The second was slightly more expensive but also had what most of us liked. So as its the middle I will only guess $250? Nothing is set in stone.
The E12 is a flagship portable amplifier and NOT a replacement for the E11. An replacement would mean an amp that was also portable wth similar function and featres in the same price bracket.
E9 to E90K is an "upgrade" or replacement.
E7 to E17 IS NOT an "in line upgrade" or replacement as E7 is $77 and E17 is $130-$150
E7 to E70K(not released yet) would be a direct replacement.
At that pricepoint, I would like to see treble boost added and see how it compares to the Headstage Arrow as this would not be in the budget category like my E11.