I messed with turnips a few times to make a majority of bells. Stopped when I had about 75 mil or so?? I'd usually just buy whatever price she sold at in bulk, literally plopping turnips all over free spaces on my island and then I'd look for someone with high turnip prices (think I usually settled between 400-550 range). I remember paying for private sessions at the time because I obviously had to take multiple trips, and didn't want to deal with other people flying in. It was definitely an investment but I just like not having to worry about bells anymore, and don't really see it as cheating or anything since it's a part of the game. I haven't used her in years though and don't think I plan to since a majority of my island is decorated and my free spots aren't near the airport anymore. Not to mention whenever I did use her I'd have to time travel because I'd be busy or just never awake by the time I logged onto the game naturally lol.