It really depends on your level of comfort and the time of the year. Food, Stay and a rental bike on per day basis around August can be anything between 2k per day to 5k per day depending on your choice of services
It depends how you make your journey are you willing to sacrifice your comfort and what you want out of the trip or it just a exploration trip. Happy Travelling!!
Goa tour packages can cost anywhere between Rs.25,000 to Rs.1,10,000 depending on the kind of Goa packages you choose. you can also visit here - https://www.tripoto.com/goa/tour-packages