For guidance on pricing your eBook, please read this blog post: Important notes about pricing your book.
We do not provide guidance on setting the price for individual titles and strongly recommend that you research eBook prices in your category to see what is a comfortable pricing point for your prospective readers.
You will need to decide on the price of the eBook in $. You can also provide a £ and € price too if you wish.
Your price may impact the level of royalties that you receive from the retailers. There is some key information about retailer royalty rates here. See also this page from Amazon, detailing royalty rates for sales in different territories.
If you enrol in Amazon’s KDP Select program, you can list your title for free for 5 days during a 90 day period. Otherwise, you cannot list your book for free on Amazon. They may price match down to 0.00 if other retailers list the price as free, but this cannot be guaranteed. Amazon are also inclined to threaten to withdraw your book from listings if you offer the book cheaper elsewhere