I understood quite incorrectly the reward/freedom system. I thought the dude needs to give her a portion of his profits. Now that I think about it, that would have been a kind of meaningless system with any master that's less than virtuous. However, it actually works by magically judging how valuable the master considers the slave's performed work to be. If she already made 25k in a single evening, it won't be long until she has got the whole 800k, assuming the dude continues to be as grateful as this. Who knows, if the dude is a long-suffering virgin and she manages to visit his bed successfully, she might shorten her debt by 100k, haha.