Due to the lack of clarity of the China Airlines website, it is better to book through the regular Czech search engines. It is usually worth booking 2-4 months before departure for the lowest price.
For travellers from Central Europe, the direct service from Vienna to Taiwan is particularly interesting, and there are also flights to Amsterdam and Rome. China Airlines is mainly used on flights to Taiwan or the Pacific islands of Palau and Guam, where they often have very good fares.