Go for beach huts buddy. Don't stay in a hotel. You'll have your room just by the beach at a dirt cheap rate. If you're in north, go for Arambol Beach. Room costs 700-1000. If south, Agonda beach 1000-1500
You can find many cheap places to stay in Goa in booking.com. Would personally recommend you to stay in South Goa as the South Goa beaches are relatively empty. Use the below link to book your stay from Booking.com and get 1k off:
https://www.booking.com/s/34_6/dipaya95