For a while I wrote a bot that would scrape ebay for textbooks and send me an email when it found a textbook that I could buy and resell to a third party (chegg, amazon, whoever) and make more than $10. At one point I was buying like 5 textbooks a day, many of them I sold for $20-$30 more than I purchased them for. And I had it all automated to the point where if the all the parameters were met the code would actually buy the item for me (although most of the books were just emailed to me for me to review). I stopped doing it because it got pretty stressful for me, and became a bit of a distraction from my regular job. I was going to try to bring in my 16 year old brother to manage it, but he didn't have the hustle in him...
