My latest tip is www.buch.ch
I needed a textbook for the course I am taking and checked around online:
At the University of Victoria (BC) book store it was $124 CAD plus an extra $60 CAD in shipping fees. Plus I would then get a 60 CHF customs taxes bill after the book arrived.
Amazon.co.uk did not have the latest (2005) version
Amazon.ca it was $81 CAD not including the delivery fee (and customs taxes)
Amazon.de it was 81,99 EURO not including the delivery fee (and customs taxes)
At exlibris.ch and books.ch (orel füssli) they did not have it.
At buch.ch it was 77,90 CHF with delivery included! I ordered it there and it arrived in 4 days and as the site is SWISS there are no customs taxes.