I feel like giving it for free to as many people as possible, however the changes of getting it in the hands of as many people as possible may be very costly and if I sell it then that can cover the costs of reaching more people with the message.
This is a hugely important question. Thanks for asking it. You have to first understand the goal of your book. Book sales are a terrible return on investment for 99.99% of authors. The real value is in growing your business and creating new opportunities for more substantial returns. You can often put the same amount of energy into selling a book (and gaining a few bucks) as you would into creating a new client (depending on your business that can be substantial revenue).
So know your goals. If your goal is to use your book as a lead generator for your business, then sure, you want to make it available for sale wherever people buy books (at least online), but you want to get that book into the hands of as many potential clients as possible. So plan on giving away lots of them for free. To do that, you're going to need a printing partner who knows how to get you fantastic bulk discount rates so you're spending no more than a few bucks a book.
What you also have to consider is that if your book is going to be your calling card, it has to be exceptional. Not good. Not alright. But exceptional. It has to capture the essence of you. Your voice has to resound through the writing. And it has to be a page turner. So hire the right expert or team to help to ensure you are showing off your brand in a way that excites the kind of people you want to attract.
Feel free to get in touch with me for more thoughts in this direction. This is the world I live in.