Hey, You can get number of Ideas and suggestions from the graphic design communities like Behance, Canva etc.
Try to join the Social Media groups for luxury/creative art works for your book. I recently printed my PDF book through online at a marginal price at https://www.newprint.com/book-printing

First of all, the Web to Print or Packaging Industry has massive competition in the market. If it started recently, try to provide better service with a lesser competitor price.
Concentrate more on Customer Life Time value (repetitive clients) rather than acquiring new customers.

Understand the local and Industry Leaders the market and their service & price strategies Eg: https://www.moo.com/us/ https://www.newprint.com/

All The Very Best

One can find many companies when looking for custom packaging boxes.
But picking the right service provider is complicated.
Things to consider:
>> Print & Paper Quality
>> Mini Order
>> On Time Delivery
>> Hidden/Delivery Charges
>> Service Support
>> Production Status etc

Most of the customers didn't find the difference between the actual printing company and a print broker. It's always good to have proper research on TrustPilot reviews, Website, and Google reviews.

These are the actual printing websites I had used before, and I am satisfied with the print quality & service both in US & Canada.
https://www.newprint.com/
http://moo.com/
https://www.newprint.ca/