I found mine at a low price. Dont spend too much money, because the Imperial models date from the 1930s-1940s.
They are unique in size and weight, and very well made, but after so many years, no accordion is expected to be in perfect condition.
Unless you are prepared to invest some money in repair. That is possible, mine is in a remarkably good state, except for the crumbled / dried out wax.
The bellows, action, pearloid, piano keys, ... all is in very good condition, except the crumbled wax. I think rewaxing would restore it in very good condition.
But Im a CBA player, and the Imperial are PA. I just bought it to take it to some artisan accordion makers, to show it is possible to make 2,2 kg chromatic accordions with 25 notes (and 8+8 !) + 12 basses.
Some day, I hope to get a CBA (with 25/26 notes) and with 12/14/16 basses for a comparable size and weight.
This will not be easy because accordion makers will have to make new building schemes for such an accordion.
This Hohnica 12 bass had a very interesting PA layout, starting with low G3 (+ 12 basses), but 13 lbs (!), way too heavy (that would be around 5,8 kg ...)
http://www.westmusic.com/p/hohner-1303-red-hohnica-12-bass-piano-accordion-100801
This makes it a more interesting range than the Imperials (who started with a C note)
Thats what makes the Hohner Imperial I so unique, the makers tested the limits. (The Imperial I and II(a) models were aimed at backpackers and travelers)