Age and Condition: Older accordions that are in good condition can generally command higher prices. The age of the accordion can be identified by looking for the serial number, which can often be found inside the instrument.
Model: Different models of Hohner piano key accordions can have varying values. Some rare or sought-after models may be worth more than others.
Material and Intricacy of Design: The type of materials used in the construction and decoration of the accordion can also influence its value. Instruments with ornate designs or inlaid decorative materials may be worth more than standard models.
Brand Reputation: Hohner is a well-respected brand in the accordion world, and their instruments generally hold good value in the market.
Region and Local Demand: Value perceptions and market prices can vary across different regions and countries due to variations in supply and demand.
Generally, a Hohner piano key accordion made in Germany, in good condition, and of a desirable model, could potentially be worth several hundred to a few thousand Euros or Dollars. However, it's always best to seek an evaluation from a professional appraiser or experienced buyer who can assess the accordion's specific characteristics and market demand to determine its current market value.