How do you find the value of an antique Hohner Student IV accordion made in Germany?

I have one that I heard came over during WW! and may be even older than that. The new ones from China cost $299 howeve3r my antique one is in perfect shape. I have heard that unless they are from the first few years after 1832 when first made, that their value may not be that high- but it is worth restoring.