Students can always access digital copies of open textbooks for free--usually as pdfs or epubs. However, for those who would prefer to read these texts in print, other options are available as well. Students may choose to print the text for themselves at a shop like CougarCopies. Self-publishing services at Amazon, Lulu, and BCcampus may also provide the option of ordering the text for the cost of paper, ink, binding, and shipping (usually around $30 to $60). Ultimately, because the authors of open textbooks choose to distribute their work under Creative Commons Attribution licenses (CC BY), no restrictions exist for printing and online distribution.
WSU Libraries has ordered print copies of several popular open textbooks (see below). If you're curious about any of these or need to use a copy for class, feel free to check them out at the library. Please note also that, in some cases, errata or addenda for the textbooks are published on the OpenStax website.