I guess it would depend on how fast you can write new books.
(I should finish my first book in about 2,000 years, maybe longer.)
I would like to see your first book stay below $4 as an introduction to your future books.
After that, up to full price (except for your friends here at MR) or $7.99 which ever is lower.
Paper books at $9.99 or what ever.
I guess my point is that I would like to see a low $1 to $3 introductory price on the first book. And leave it low. Books after that should be higher, if possible.
If I can read a chapter or two then I really don't feel like I'm wasting money when I pay $6 or $7 for a new authors first work.
I know, the only price that some will pay is "the lowest price".
Even free is too much if I don't like that first page or the first chapter. I don't download just to say "look what I've got".
P.S. - I do have you book.