About the price different, the cost difference come from the metal case and the driver, accessories,
1, About the metal case, you should noticed that the FH5 includes 3 different parts and the shape is far more complex than our F9/F9 pro, we call it "TriShell", if you get both on hand , you will figure out what a huge improvement based on F9 PRO.
2,About the drivers, this time, we used a very famous ED BA for the middle , the ED driver is quite expensive , plz noted that not every BA cost the same.
3, This time the FH5 comes with a very good cable and better package.
BTW, you guys can waiting for the reviews and I believe you will not disappoint about FH5.