Understanding what happened could be worth a lot more than $50m, or twice that.
Major issue with the airframe, or propulsion? Very important to understand that. There are a lot more of them flying around.
A third party's influence and/or an attempt to steal the plane? Whether that ended in a crash or a successful theft, we need to know everything we can about who, what, why, to what end. If it was stolen and landed (extremely, very unlikely), gotta know where and why. If it went in the drink during an attempt, still have to understand what the game plan was.
Suicide? Hiding in regular traffic, then flying low and into the most remote, deepest water possible in the interests of never finding the plane - the better to make sure family collects on insurance money? Would be good to know, and will remind airlines to get harder about knowing their pilots and the pilots' current circumstances.
Regardless, the navy assets out looking are using the whole thing as an excellent training exercise. Lots of smart people have had to whip up new ways to think about what happened, using only traces of satellite/comms data.