I ask because our German publisher is planning a very large first printing of the German translation of one of our books. The print run is pretty much the same as the US print run, which surprised the heck out of me, given the population difference between US/Canada and Germany (333 mil vs 82 mil). How large is the German book market? How many books are Germans buying each year?
2005 the german booksellers had a combined turnaround of 9,2 billion euros. Source: http://www.boersenverein.de/de/64584 (Boersenverein des Deustchen Buchhandels)
Unfortunately, this site does not give a number for the books sold. German Wikipedia (Buchhandel – Wikipedia) tells me that “On average, every german citizen pruchases four books per year”, which would be a total of
240 million books sold yearly.
The Wiki article cites no source for this, but if you divide the 9,2 billion euros by the 240 million books you get an average bookprice of 28,75 Euros, which seems totally plausible considering that hardcover books and scientific literature often cost in excess of 40 euros.
On a side note, I’m happy that after only one day of lurking, I can already introduce myself to this great board with something useful 
This IS a board about hemp growing and marihuana subculture, right? RIGHT?
Let’s be clear–it’s only about heterosexual hemp growing. Read the title carefully.
The 9.2 billion turnover of the German booksellers probably include non-book items such as audiobooks, so 28.75 EUR would be a bit of an overestimate. (e.g. the hardcover Harry Potter books of the last few years are in the 20s €, and the new HP hardcover is provisionally priced at 30 €. Most of bookstore turnover seems to be in paperbacks, though, from what I see in bookstores.)
What’s the general field/type of the book mentioned in the OP?
A graphic novel for kids.