Well it's depend upon u that which type of hotel property u r booking..if u r a budget traveler then u can save money by staying in hostel instead of costly hotels..and for 2pax I think its 60-70thousand rupees if u do a proper planning
The first thing is planning for Andaman trip itself is a very costly idea. So, you should not expect anything such as budget travelling or backpacking will be cheaper. For a single person it costs nearly about 30k. So calculate yourself how much it will be for 2 person.