Currently, the system for ISBN registration is configured to only accept prices in USD. This limitation means that if your book's price is originally in a different currency, you would need to convert it to its equivalent in US dollars before entering it.
Alternatively, you can select "Write for info," which indicates that there isn't a set price or that the book is free. This choice can be particularly useful for authors who are still deciding on their pricing strategy.
It's important to note that the price you choose for your ISBN registration doesn't restrict you when it comes to pricing your book on other platforms, such as Amazon KDP. The price listed in the ISBN registration serves more as a general guideline, helping potential readers understand the price range of your book.