Tom
I’ve used KitchenOwl for this (I’m the developer), it’s FOSS but doesn’t support multiple currencies. It has an overview where you can breakdown costs by categories and see who ows whom.
I always liked planetary annihilation. It is really easy, looks decent, and has a native Linux version. That it’s placed in a planet system makes it different to many other RTS.
Thanks! I’ve explained how to manually install here in a bit more details. But I wouldn’t recommend it, like you said it will be annoying to manage if something changes, and I honestly would stick with grocy in that case as you don’t loose all your recipes and so on.
Python is not the ram friendliest language so it’s using somewhere around 200-400mb of ram. Although there seems to be a bug for some people where it uses much more.
You could give KitchenOwl a try (disclaimer: I’m the developer). Has apps for iOS/android and other platforms.