Yes; the hours needed to create a Children's Book can vary considerably, mainly because a single book is, in reality, many separate art projects, one for every page! The number of elements (figures, objects, scene details) included on each page of the story, how much story text is added, and what level of art style and detail are preferred will all affect the hours needed to fill that empty page. There are three hourly ranges (based on previous book projects) to give a good starting point on cost levels. By looking closely at the samples, you can see the differences in style levels:
Level 1) Simple clean line art with nice graphic basic color fills and less detailed backgrounds.
Level 2) Added characters and scene elements; characters, elements, and backgrounds begin to gain more detail and color.
Level 3) High-Level more painterly art with no line art; a very detailed technique and richer looking scenes and characters.
Two important points to consider:
1. Stories with repeating characters or scene elements (clouds, trees, scene details) can sometimes come in below these starting quotes, because working with digital art we can often reuse faces, figures, etc. to speed up the process with no loss in quality of the final work.
2. All three cost levels include initial sketching, a rough storyboard indicating layout and text placement, and final completed pages with the finished story text in place; Front & Back cover art and design is also included at no extra charge.
That being said:
Level 1's more graphic, simplified figures and details will generally take about five (5) hours from first sketches & storyboarding to final pages- $300 per page. (+free cover art)
Level 2's increased scene and character development takes about eight (8) hours for the same sketching, storyboarding and final art & text- $480 per page. (+free cover art)
Level 3's highest level of painting and overall richness of detail comes in at the most time involvement, about 12 hours from start to finish- up to $720 per page. (+free cover art)