Here’s a reference for you for publishers, its the Alliance of Independent Authors: https://selfpublishingadvice.org/self-publishing-service-reviews/
The above reference will give you an alphabetical listing of self-publishing companies. You will notice the grading system. The ones in green are vetted to be ethical and of high quality work product.
I asked my Higher Self, The White One, to give me a formatting company, and make it really easy. I just typed in the words and found “Formattingexperts.com”. They are based in Warsaw, Poland, with a New York City office. They were a dream to work with. High quality work product. Their turn around time was lightning fast. The first graphic artist nailed the cover design. I was told if I didn’t like their work, I wouldn’t have to pay them a dime. I paid them more money than we agreed upon because Time Travels was a very difficult book to format. They were happy.
Now, viewing their website, I see they have a pricing page and it shows the author can make payments in installments.
