A few years ago, I spent most of my savings on The Lunar Chronicles by Marissa Meyer (Cinder, Scarlet, Cress, Winter, and Stars Above; I didn’t get Fairest), read them all, and loved them…though I didn’t reread them and sold them some time later.
And what was the first series you spent most of your savings on?
Personally: The Pendragon series of YA novels. I poured my spending money into that series and even skipped school of the day Soldiers of Halla was released. My English teacher at the time was also really plugged in to YA literature at the time, so she knew exactly why I wasn’t in school and the first thing she asked me the next day was for my thoughts on the book.