I had the same problem in my first playthrough. Second time, after following the advice I got to focus on the bar as early as I could, I got closer but still ended up being in debt after the aforementioned accident. Third time, I found that the best way is - combined with the general advice about the bar - to simply limit yourself to interacting with just one of the girls per day once all of them have moved in. Sure, the plot may move forward a lot more slowly but I managed to make just enough money when it came to buying the elf in question.