@jclarke think of cost of time. If taking a bus makes you save 5000rs per hour then totally worth it, if its below 500 bucks of savings then u r selling your 1hr worth of time for Rs. 500 which is underpriced. You could rather take a cab and spend time reading.
apart from that nothing wrong in saving money and living a frugal lifestyle. just dont confuse being a minimalist with being frugal. e.g. buying a quality chair which will add years to your backbone vs. a cheap chair, or a place to stay in city center which saves commute time vs. outskirts
other way is to explore FIRE and leanFire