I know everyone's on board with libraries and I don't need to hammer home how not only amazing but also necessary they are, but here's a fun case study: the amazing book Our Bodies & Other Fine Machines by Natalie Wee. Published in 2016, now out of print, $750 on Amazon (+ $3.95 shipping). The DeKalb County library system was able to get me a copy from the King County library system in Washington for $3 and a little bit of patience. Thank you to Natalie Wee and the DeKalb and King County libraries! I will return it on time and unmolested.