In earlier threads here, about last year, we were told the market for Germany proper had crashed and it apparently still remains there. Part of the picture was that in many cases on German
ebay, there were no buyers. Go there today (search "Deutsches briefmarken") and you will find postcards, cheap covers, a very few (overpriced) stamps offered by amateurs and little else. That's why the seller is on US
ebay and there is no backlink offering them on German
ebay.
The prices for the colonies, (sound) German States and German related areas have weakened. I don't know if Michel (always inflated in pricing vs. real prices) or Scott have dropped prices yet to reflect that change.