Proofreading is the vital last step of the book editing process. After your manuscript has received its professional edit, your book proofreader will perform a final review to fix any remaining mechanical and grammar issues before your book is printed and published. Proofreading is not a structural edit and instead focuses on eliminating minor mistakes and inconsistencies.
I would absolutely encourage authors to find someone who fits their budget, offers payment plans and will work with them to get the services they can afford (some authors might be able to get away with just a manuscript evaluation, for example) I have to agree with the previous comments. Someone who is working for two bucks an hour can’t possibly be a professional, no matter how fair their prices, and that does not bode well for your end product.

There seems to be something half-way between beta-reading and development editing. I think it’s right for many new writers — I’m just finishing my first book, and was not about to pay a real development editor, but beta readers weren’t engaged enough (especially friends unwilling to point out the negatives). But it this kind of editing doesn’t really have a clear name.
The other thing I really like is your breakdown of the types of editing available. That’s what I find needs to be explained the most. Especially in business editing, you get scenarios when someone thinks a document needs “a proofread”, when it really needs a copy edit or even a heavy line edit, and you have to justify the cost or the time it takes to complete it.
2. Copyeditors aren’t the last line of defense when it comes to a book’s mistakes. Formatting, which is done after an editor has done their job, can lead to unintended errors being introduced into the text. That’s why it’s important to hire proofreaders to comb through edited text *after* the book has been formatted for print or digital. Proofreaders are your last line of defense—but they’re human too.