The price of a meal depends entirely on where you eat and what you order. A nice quaint restaurant will cost you between Rs.300 to Rs.500 per person depending on what is ordered. Eating at the local village market will be much cheaper and most Andaman islands have a number of small eateries run by locals that work out easy on the pocket.
Sea food is more expensive in the Andamans compared to the mainland due to heavy demand and less supply.