I also get mine from Amazon. The problem with buying books from Amazon is when you only need a book or two. Sometimes, your shipping fee is higher than the price of your book - that goes for both priority international shipping or standard shipping.
Another problem with standard shipping is that it takes too long to arrive. I once had a project wherein I needed a book for reference (yes, I'm that kind who prefers books over the internet). What happened was the book arrived after 2 months. By the time the book arrived, I was already working on a different project where I no longer needed the book.
Another problem with standard shipping is that books sometimes get stuck at the post office. Yes, it happened to me. Instead of simply waiting for the book to arrive at my doorstep, I still had to fetch my book at the post office, which is less convenient. Yes, I'm that lazy.
So here's what I did after discovering those inconveniences:
- Like what what @datenshi mentioned, it would be better to order in bulk so you wouldn't have to pay for the expensive shipping fees every time you need a book.
- Order books with your peers. Similar to the first point, but this time, you get to share the shipping fee with somebody else. This works best when you only need a few books and want to pay only a percentage of the total shipping cost.
- Also connected with #1, Plan ahead. Whenever you find a good book that you want, but you know you won't be able to read it within the next few weeks, list it down. When you already have a good list of books that you want, that's the time when you can place your order.
- Use alternative shipping methods. The last one I used is Pobox.ph. With Pobox.ph, you order books from Amazon and instead of sending the books to your house/office in PH, you have your books delivered at their warehouse in the US. They then deliver your books in a month or less right at your doorstep. Plus, the shipping fee is cut in half. There are other shipping alternatives, but this is the one I used because their customer support is very helpful.
- And yes, don't go for books that contain topics that can go obsolete very very fast. That's the time when I prefer the internet over books. For example, I prefer reading about various JavaScript libraries on the internet.
I've also tried ordering on A1Books through Google Checkout. It took 3 months as far as I can remember. When I tried ordering on bookstores connected to Paypal, they didn't have the books I needed.
Oh, and one more thing: it would be awesome to work for companies who invest on lots and lots of books so you wouldn't have to spend for the books yourself.