TorUser doesn’t have access to your current user’s display. You need to first give access using something like xauth or xhost.

That could be part of it but I’m not sure it comes close for most ebooks. A lot of these books are professionally typeset and laid out pdfs, not sloppy calibre conversion pdfs. I don’t think Amazon sells in pdf. As far as bounty forums, I just looked at one site over the last three days. It averaged 365 books per day, 199 per day with 2023 publication dates. That seems like a lot of successful bounties!