Buying ebooks from Taiwan

Good afternoon:

I want to buy "learning perl 6th edition, ebook version", (http://shop.oreilly.com/product/0636920018452.do# )
it is $15.99;
however, I am a Taiwanese, so I have to pay it with Taiwan dollars,
Do you have a fix exchange rate between US$ and Taiwan$, or it just depends on the daily new exchange rate?

Besides, I live in Taiwan now, and if I buy it, the only way to pay it is using credit card, isn't it? Every credit card of every bank can do it ?(sorry for this stupid question)
Do I need to pay additional fee (apart from $15.99) because this is a cross-border transactions or something else?

Last, If I have bought it, can I print it?

Thank you very much!

Jeff Chu from Taiwan