If you are planning to self-publish, unless you plan to concentrate on print publishing, you will need to look into your options on pricing ebooks.
In my opinion, ebooks are the reason self-publishing took off as it did. First off, ebooks are relatively easy to create, and second the per copy cost to replicate them, once you have the files in place, is zero. This means that if you are not a well known author, you can price your book very competitively (as low as 99₵) and thus compete with better known but more expensive writers. The big publishers seem to want ebooks not to sell especially well, at least when they are new, because they price them so high. Quite often the ebook version is more expensive than the paperback version, defying industry past practice that a higher price meant a more expensive to produce product.
Here's the Amazon page for Twilight, a best seller first published in 2006. The hardcover is way more expensive at $22.49 but the Kindle book is more expensive, at $10.99 than the paperback is at $9.43! And by the way, the ebook price is the same on Barnes & Noble and Google Books.
Publishers fought with Amazon to be able to control the price of their ebooks. Publishers wanted to be able to protect hardcover sales, which are very profitable. Amazon lost that battle, but you will notice Kindle books usually say "price set by publisher."
The good news is, if you're self-publishing, you (mostly) control the price! On Amazon, you get the best deal on royalties by pricing your book between $0.99 and $9.99, which is frankly, the range it's best to be in unless you're already a best-selling author.
You also control when the price changes, which means you can experiment with different prices. Be aware that Amazon price matches, so if your book is cheaper in other ebook stores than it is on Kindle, Amazon will drop the price of your Kindle version to match the others' lower price. That is, by the way, the method used to make a Kindle book free on a long-term basis. A book that is in Kindle Unlimited can be free for up to five days every three months, but except by using price matching, you cannot make a Kindle book always free, It is only because other bookstores allow free ebooks that price-matching can work to make a Kindle book free.