I'd like to add a couple tidbits into the PLB discussion here…

Yes, they are high-tech and they signal Search and Rescue very quickly to your specific location, which is why they are so expensive. They do their job and they do it well.

But a PLB is not the only solution for attracting attention to yourself. As others have said, a good signal fire would work as well, or snap the mirrors off the car and start shining everything that moves. Another great option is to have one or two (or more) RescueStreamers. These aren't just made for water, and they pack small and are much less expensive than a PLB!

Note that Kati Kim and the two children were spotted by a chartered helicopter by waving an umbrella with a reflective "SOS" on it. Using the RescueStreamer(s) to draw an orange line or "V" in the snow would have made a much larger, more noticeable, and passive signal. Hell, you could even throw one up a tree to give your signal a vertical aspect.

As Doug states in several locations throughout his articles, preparation involves redundancy. You don't just get yourself a PLB and think, "Hah! I'm set for every situation!" The moment you start thinking that is the moment the PLB's antenna falls off or the battery falls out and rolls off a cliff. The idea of emergency supplies is to give yourself several effective methods to get yourself out and to keep you alive until that happens.

To conclude, while being a great addition to any survival kit, a PLB is not the only option to consider and it is also not a 100% solution to every problem.