Top 10 Most Expensive Trilogies Sold by AbeBooks
7. Douglas Adams’ Hitchhiker’s ‘trilogy’ - $1,250
Not really a trilogy as Adams later wrote parts four and five but never mind the details– these three first editions were all signed by Adams. Of course, the books were The Hitchhiker's Guide to the Galaxy (1979), The Restaurant at the End of the Universe (1980) and Life, the Universe and Everything (1982).