https://www.humblebundle.com/
Humble Bundle is a site where you can get e-comics, books and games for low cost, sometimes only limited by how much you want to pay. Some of the proceeds go to the charity of the publisher's choosing. Right now, the big thing (for me anyway) is a whole whack of Valiant Comics.
Valiant Comics were big in the early '90s and has come back in a big way in the last couple years. Their Humble Bundle gets who a whack of their current books and some of their older reprints for as much as you want to pay. If you pay at least $15, you get the whole kit.
https://www.humblebundle.com/books