I wrote a python script that I run locally which scrapes read.amazon.com (think this is the URL, I’ll double check when I’m home). Kindle highlights are automatically synced there. The Python scraper extracts all highlights into a json file and stores this in S3.
I have a Lambda function which runs daily, selects a random highlights, and emails it to me. I’m using AWS SES for sending out the emails.
I think it’s all essentially free tier AWS stuff, so basically 0 cost. I’ve not fully automated it, I need to run the scraper manually but that’s easy enough to do whenever I’m at my desktop.
It’s a bit hacked together but it works lol.