Hopefully this is not too much off-topic but one of my best school friends was murdered on flight UTA772 in 1989 (he wasn't the target of the bomb, just one of the consequences). Seven years later his mother forwarded me his camera that had been discovered in the wreckage. It was pretty beaten up but it seemed to me that there was still a film in it. I managed to ease the film out undamaged but by now it was way past its process by date and had been lying in the desert for a while so I wasn't at all optimistic about the latent image. With technical help from Kodak and a very good lab we eventually managed to get some usable images off the film. To my amazement there was, when greatly enlarged, one picture of him. Grainy and colour distorted but definitely him. This picture was some source of comfort to his family as his body was never discovered which, as is always the way with these things, adds immensely to the distress.
So on MH370 there might be other useful sources of data in the wreckage apart from the FDR.
Often the wreckage itself tells a big story, assuming most of it can be found in a debris field. It can certainly say whether it broke up in the air or hit the water intact, for a start. Then you can look for bomb explosions or other types of explosions. Even the location of the wreckage would fill in large parts of the story which is currently unknown.
The interesting thing to me is how much money,collectively, are we (and the term is loose because I don't know who is paying) prepared to spend to find this wreck?
The other way of looking at the expense is "How much are we willing to pay to prevent another such disaster?" (assuming it wasn't a conspiracy of the pilot).
So on MH370 there might be other useful sources of data in the wreckage apart from the FDR.