I'm confused about the price number in NT$.
About the currency used on our website we are very sorry that the payment gateway provider does not allow us to show our check out in US$. The prices are in NT$ (New Taiwan Dollars) we are reviewing once a month the conversion and our prices in USD are pretty accurate, it can have a variation of very small amount according to the fluctuation of the currency within the month. You can use this currency converter to translate the amount into your own currency: https://www.xe.com/currencyconverter/
I can't pay via credit card.
Maybe because the shop is in NT$ (TWD), and the security system is triggered. Either try another card or call your credit card customer service to unlock it.