My husband and I exhausted every option when moving our small (yet more than we could cram into suitcases) shipment last August from Portland to Zurich. Here is what we did and what I suggest for you, too.
1). What airline are you flying? We flew Continental and they allow boxes as checked baggage. We checked numerous boxes (up to 70 lbs each) and it was cheaper than shipping. The only catch is that the airline won't be held responsible for damages to items in boxes. So be sure to pack carefully.
2). If you must ship, use the United States Postal Service Flat Rate International Priority Mail Boxes. Check prices at
www.usps.com. It works out to be the cheapest. DO NOT USE FedEx, UPS or DHL! FedEx would have been about $300 per box for us and the kicker is that you are charged on arrival! At least 20-40 CHF per box.
3). Consider how long you are staying and how costly it will be to send all of these things
back. Postage in Switzerland is not cheap and you will also accumulate things while you are here. It is a tax deductible moving cost, but if you're not staying more than one year, then I doubt you will not be able to make the deductions for both moves.
4). Book Depository (as mentioned by others) is a great resource and I've had positive experiences with
www.amazon.de. The shipping was reasonable and I was not charged tax on arrival for the packages from either of these sources. Naturally, amazon.de is in German, so if you don't read German, search first on amazon.com, copy the ISBN and then do a paste and search on amazon.de. It will pop right up!
Good luck! What brings you to Switzerland??