https://www.desidime.com/discussions/looking-for-best-flight-offers-for-single-domestic-booking?page=1#post_8807293
Use kayak or sky scanner, you will get the best deal.
These will redirect you to Agoda or goibibo which offer cheap tickets as they buy in bulk in discount.
If you buy directly from airline you will have to pay around 1.5 times.
When booking from this method sometimes only 1 ticket can be booked at a time.
