Many people create their first ebook using free software, but then later invest in more advanced programs to make it better. Some of these apps have you pay for them, which is totally okay! If you feel that your app is too expensive, there are many websites with online coupons or discounts for those apps. You can usually find sites that feature discounts by searching “app giveaways” or "ghostwriters for hire." By offering a small discount at least once per month, you will win back some of those hard-earned credits from the app. These rewards can include either a one time use license or a monthly subscription if they offer one. It really doesn't matter, just pick one that works best for you! There is no obligation to buy anything beyond just creating an account!