What is the Most affordable book publishing?

The question seems to indicate you are interested in self publishing your book.

Many companies exist that will help you with the publishing process - from editing your manuscript to creating the design for your cover and interior, to setting up and handling distribution and fulfillment tasks.

There isn't an answer to the question - it will take research, but we can provide details on the items to watch for (and to make sure you get answered).

Publishing costs (the upfront costs) of building your book are one component, the cost to you the author to purchase books is another, the final piece of the puzzle is the per book profit when a book is sold through distribution. These costs and profit differ from publisher to publisher - and sometimes from package to package at a publisher.

Regarding distribution - all self publishing companies have the same reach (regardless of what they might say). The 'dot com' versions of stores will fully support your book, it will be available to order in most B&N stores and some brick and mortar stores, very few - if any - brick and mortar stores will actually stock your book.

Here's a link.