Balcony being enclosed = loss of view and sun

We have bought a unit in NSW and have learnt that our neighbour is going to enclose their balcony. One of the reasons why we bought the unit was for the view and by enclosing their balcony we will lose about half of that view and some sun. However it seems all body corporate and council approvals are in place. 

We have asked for compensation but this has been refused on the basis that the body corporate and council approved the work years ago. (Other owners in the building don’t care as they live on the other side of the building so aren’t affected). The strata manager says that we would need to take the council, the body corporate, and the original owner who obtained permission (unit has been bought and sold twice since approval), to court if we want to pursue the matter.  

A realestate agent told us that the value of our apartment will drop about $50,000 once that view is gone. 

Do we have a leg to stand on if we pursue the matter?