It's not apples to apples of course but that's well within the ballpark of what spacex spends mostly just shooting stuff into orbit in a year: https://spacenews.com/spacex-and-the-categorical-imperative-...

Especially for a first time in all of humanity type of mission, half a century ago, which yielded brand new data on faraway objects we'd never had, and considering it's still going and reporting data, it's arguably a bargain basement price for such a thing.

Not to mention that it has a chunk of highly radioactive plutonium that acts as a battery / power source. That whole thing is nuts that it got built, "shipped", and still works ~50 years later, approximately 1.21 jiga-kilometers away from Earth.