Hey Safia, Would suggest you to stay at Hampi Island as you will find alot of affordable options out there, for eg:
Nargila, Uma Shankar, Murali, Mowgli & Shanti guest house. They also have restaurants inside the premises. All these guest houses are close to one another. So just in case you don't like one, walk to another one. Minimum charges will be around INR 1000. Since you are staying for 3 days, you can negotiate more. Have fun in Hampi :)
Best is download the oyo app..There are multiple options at affordable prices on oyo.It is a very reliable app;i am using it from last four years.classy hotels at low rate..
Hotel Malligi is an option if you are looking for safe and affordable option. But it is in Hospet and you need to travel to and fro which can be costly affair if you are planning for long stay. Hippie island is an option if it is opened up. My last visit during August, it was closed.