The great thing about e-books for authors is that you can offer them at a reduced rate because they don't cost anything to produce.
Anyone who has ever self-published an e-book knows what a nightmare the formatting can be if you don't have formatting software package like Scriveners. Especially if you have pictures. Once you've published your print version on Amazon's Createspace they tell you they will format your manuscript for Kindle. In my experiences, it doesn't work as it should and when you check on the online preview screen, your book is a mess.
I download and try to read many books that are not correctly formatted and I empathize with the authors who eventually gave up and just decided they would have to live with it.
One of the most annoying factors is that Kindle uses a different language to Barnes & Noble, and Apple, and although Kindle dominates the e-book platform, it hasn't totally taken over -- yet.
Those who use Scriveners swear by it, but it's not essential.
I can Help
Once you understand how different the layout is, and if you have a good knowledge of how to use Word, formatting doesn't have to so difficult. However, if you are not computer-savvy you could end up tearing your hair out over it.