Thanks. I'm just surprised that the cost of damage from seawater to a dumb rocket with a parachute and floats is more than the cost of a smart rocket making a much more error-prone landing on a tiny ship.
Maybe it helps to think by analogy. Which is harder, putting a car on a ferry to carry it across a river, or just driving it into the river and fishing it out the other end? Sure, you'll have to replace the engine and the electronics and lots of other stuff (i.e. all the most expensive parts of a car), but if you're only doing it once, it's cheaper to ford that river Oregon-Trail-style than to get yourself a ferry. But if you're doing it many times ...
The point is, there's lots of extremely high precision, expensive stuff on a rocket, that don't appreciate being dunked in water in exactly the same way that, say, your computer or car wouldn't. Those engines are incredibly complicated, high performance, and expensive, and they don't have the benefits of economies of scale like other consumer goods that are manufactured in the amounts of millions or billions per year. Each rocket has nine Merlin engines on it; that's an awful lot to essentially have to replace with every launch. The barge is cheaper.
Seems like every thing else in history has really been a missile. This thing can land, so seems like it's literally the first rocket. Do we have a definition of missile vs rocket?
A rocket is just something with a rocket engine. Note that missiles do not need to use rocket engines and rockets don't need to carry warheads.
Also, I assume it's a lot easier to be sure that the rocket's in good shape if you don't have to check the interior for leaks, and whatever chemicals seeped in with the water?