I’ve found that Bangalore can be explored on a budget if you plan the basics in advance. I usually prefer a hostel or a simple hotel in an area close to a Metro station. It saves both money and travel time.
For getting around, the Metro and local buses are much cheaper than using cabs for every trip. For food, local restaurants and small South Indian eateries are great for affordable meals.
I also avoid trying to visit too many paid attractions. Parks, markets, temples, and heritage areas can make the trip interesting without adding much to the budget.
The main thing is to plan your stay and daily routes before the trip. That helps avoid unnecessary travel costs.