Preorders are tremendously helpful for authors, because they signal to bookshops that there is enough demand for them to bother stocking the book. If you think you might buy the book at some point, would you consider preordering it? You can do it on e-book and audio book also, which are generally a bit cheaper (hardbacks are expensive!). Requesting your local library to stock it is also a huge help if a new book is out of your budget.