This is a monolithic beast of a country, one that cannot be done justice with just one trip. India is broken into 29 states, plus a number of union territories. The states have vast differences in cuisine, language, and culture, so the land often feels like a bunch of countries put together. India is a perfect backpacker destination. It has an infinite amount to offer: beautiful nature, great food, and low prices.
Budget (2018): If you eat where local people do, bargain for cheap hotel rooms, and take sleeper class trains, $20 a day is quite doable. Food is insanely cheap, with a meal usually running $1-3. Hostels can be had for $3-5 per night, and hotels at $5-10 per night. Transportation (assuming you stick mostly to public transportation and sleeper class trains) is also ridiculously cheap.
Budget (2018): If you eat where local people do, bargain for cheap hotel rooms, and take sleeper class trains, $20 a day is quite doable. Food is insanely cheap, with a meal usually running $1-3. Hostels can be had for $3-5 per night, and hotels at $5-10 per night. Transportation (assuming you stick mostly to public transportation and sleeper class trains) is also ridiculously cheap.