I second sunshower, doing it is what counts. The cost is minor, for a lot of work goes into setting up a book. Those who offer free, like Lulu Press, catch you on the per copy price, and free can't complain.
One thing they all have in common is no promotion, a major may pay for some reviews, send out free copies, but it is always the writer who must do readings, signings at book stores, visit clubs, and build a name.
I compare it to a band, your music may be great, but you have to go on tour, play a hundred clubs, and build a name.
A first book is like being a painter with one picture, it's a start. The great thing about books is they are cheap enough to give away, and that drives readership. You have to talk about your work, but when other people talk about it, that is better.
It will also show your shortcomings, and things you would do different in the second book.
First book, you will advance in a dozen directions, and become wiser.
It is not an end but a beginning.