This is a guide I wrote based on the following world record run: https://www.speedrun.com/recettear_an_item_shops_tale/run/y6pvr30m.
https://docs.google.com/document/d/12YlDoWczhH7g4avaGWaPw8gTyhi1zTw7KQrzUCkizWg/edit?usp=sharing
Due to the nature of this run, there is a high amount of RNG that you must account for. You might not sell items in time, you might have to sell items for a lower price. It is all up to you to decide whether it's worth resetting for. There are also a lot of time losses you can take to continue a run if you believe it to be good enough. A notable one is using free time that could be skipped to sell or buy instead.
Menuing is also a large part of this run. You can save time immediately by going through menus faster and more consistently.
Please contact me if there is something missing, broken, or incorrect, so I can fix it.