What $12 will get you approximately.
To touch more on this from what Marty said above. Think of going into a library wanting to find a specific book, author or such and all these hands point you directly to what you are looking for. Naturally it doesn't stop there, the pages turn where your eyes want to go and you find what you have been looking for all this time.
Just think about all the sage advice whether it is electronic, general engine maintenance (model I mean), track design, real knowledge railroad knowledge asked for so you can model it accurately, the list goes on.
I'll never forget following GRJ to see a topic about the Atlantic Steam engines design flaw. How the wires could go into the flywheel killing the engine. That is just one small thing that avoided a repair that would have had me rip some of my hair out.
There are so many more things that heck I wouldn't even know where to begin on. So, to sum up, well worth the price of admission to get a full satisfying show.