Check out my write up on Goa; stayed at Mandrem beach, pretty close to Arambol ;) Good property. Also there are many Air Bnbs around Ashwem and Mandrem. Happy travels ;)
You can check out Bloomrooms@ calangute. It's a new property, well maintained, quiet close to baga beach. Excellent stay option. I stayed there this Feb'2018. Had a great time!
Hey if you want a very cheap places to stay in goa ,then hostels are the best ones if you are comfortable with that , lot of cheap hostels are there in each part of goa, in arambol dreamcatchers hostel, happy panda hostel, no name hostel, like that lot of hostels are there , you can book room online through various sites like bookings.com, hostelward etc.
another thing is arambol and baga are bit far away so you have to decide whether you have to stay in baga or arambol
arambol is more hippie type beach and personally I like arambol more than baga and I stayed in arambol during my stay in goa.
wishing you a wonderful journey.