How much is a chromatic koch harmonica worth?

The Koch chromatic was a very cheaply made model from Hohner, they took over Koch to eliminate the competition. I have seen used Koch chromatics going for $15.00 used with no box. I bought one with a box in almost perfect condition with the original books on how to play the harmonica for $30.00 on E-bay. The new ones sell for about $80.00.