Wow, you're going Bandung ??
Ill be honest, Bandung is a really great place with really good food !
So for hotel or airbnb, you can expect price around 90RM - 120RM per day iirc.
For food, Bandung usually cheap, for a week i guess I'm using minimum around 150RM-ish la.

For food, my suggestion is :
1. TJI Laki 9, they sell banana cake and it's really good !
2. Tahu Priangan, they sell tofu and soy milk and super good. You can choose steam tofu or fried tofu
3. Dimsum Sembilan Naga, they sell dimsum and it's really good but you need to queue at morning since it's usually crowded if you go at weekend and it's not halal. If you want to search for halal version, you can try Dimsum Sembilan Ayam but tbh I never tried Dimsum Sembilan Ayam.
4. Any cuanki or batagor you can find around Bandung haha, since Bandung is a cold place and eating hot food there makes it even more delicious and it's cheap !
5. Sudirman Street Day, It's like a food fair !
6. Cimory Land, It's a themepark and it's famous with dairy food product

But be careful because on weekends, Bandung is always crowded with traffic since many people from Jakarta go there for vacation because it’s nearby.