In my humble opinion...

Your kids may not "get it," but that's ok. 

I don't have a lot of money, but there are things I'm willing to throw a few dollars at every now and then. For example, there are certain charities, like the AbleGamers Foundation, that I'll always give to or support in any way I can. (And if you aren't familiar with AbleGamers, take a minute to learn more about them. They really do fantastic work to make gaming an accessible hobby for everyone.)
It's one of the reasons why I fell in love with the Humble Bundles, and have been supporting them - and growing my Steam collection to an unmanageable size - for years now. I have supported Humble Bundles for PC games, for console games, for mobile games, for e-books and audio books and comic books and - you get the picture. It's hard for me to say "no" to a book about building my own coffee roaster for a dollar, especially when I can decide how much of that dollar goes to charity, how much goes to the creators, and how much Humble Bundle gets to keep.

Humble Bundle isn't the same beast at all that they were in those early years. They have several bundles going on at a time now, across various forms of media, and they even have a monthly subscription service. But they still do good work.
And, right now, they have some seriously cool classic games available in their Humble Sierra the 3rd Bundle.

For those of you who are younger, you might not remember the Sierra games. Those readers of a certain age, however, (i.e. old folks like me) will probably remember their first Sierra experience. Maybe you saw a friend playing one of the engaging point-and-click adventures and needed to try it for yourself. Or you got one of their games in one of those mile-long folded plastic sleeves of shareware games. For me, it was King's Quest VI. My mom bought a used car, and it was left in the backseat by a previous owner, and promptly installed by 17-year-old me on my state-of-the-art IBM Aptiva 486. (Yeah. I'm old.) It challenged me at first. I didn't have the game manual. I wasn't sure what I was doing. Why was I starting out on this beach? What was the deal with all the Alice in Wonderland references? Should I have found and played King's Quest I - V first?
It didn't matter. I worked my way through the puzzles, pissing off a "dogwood" tree in the swamp so I could pick a bottle of "milkweed" to feed the cabbage patch babies, collecting "iceberg" lettuce to throw into a boiling pit of water so I could cross it - lots of puntastic fun. It seems a bit dated by today's standards, and the graphics on those old games have not necessarily aged well. But they can still be fun, or at least nostalgic, and if you're like me you love telling your kids about everything you went through as a gamer "back in the day" while they roll their eyes and laugh at you. Now, you can show them just what all the fuss was about, while also supporting the Call of Duty Foundation, to help get unemployed veterans back to work.
So go on and check the bundle out, or one of the ten other bundles that Humble Bundle has up at the moment (including a pretty neat bundle of royalty free music loops that you can use in your own games or video productions). The Sierra bundle is worth supporting at the first tier just for Gabriel Knight 3 and Police Quest bundle, but it also includes a couple of newer games, like the 2014 shoot-em-up Velocity 2X and the 2007 FPS TimeShift.
Toss at least $12 at the bundle, though, and you'll unlock all the King's Quest games (including the 2015 episodic re-imagining of the series) as well as the first game in the Gabriel Knight series, Gabriel Knight: Sins of the Father and the Quest for Glory series (in the middle tier, currently setting at just under an $8 average to unlock), a groundbreaking RPG series that let you create your own character, and carry over experience and items from one installment to the next. (It may not seem like a big deal now, but trust me, in the 90s it was huge.)