When considering whether you should do just an eBook or a combined eBook print run, here are some considerations to weigh in your decision-making process.
Are you a first-time author without a following or platform? Releasing your first book as an eBook and selling it for free or $2.99 or less will built a following for your next book. You can begin to build your platform and create a following.
Are you writing a book series? Again, an eBook enables you to build that important following without spending a bundle to produce the book. You can release the first book for a lower price or for free and then increase the price on the next one.
Are you a first-time author who can't get a publisher's attention? You can produce your ebook for a lower price and release it to build interest and create a built-in audience for you to prove your value if you opt to go traditional on the next book.