Well, if you want to motivate a child, perhaps you do have to have the latest and greatest, or at least something with some cool factor.
I'm not so sure. The "cool" part of playing with the old machines is that there was little abstraction back then keeping you away from the bits. If you poked the right memory location with the right number, the pixels on your screen would change. Poke another bit and you'll hear a click on your speaker. That's very cool, in my old timer opinion, and something the kids today almost never get to see. Everything they're learning is so abstract that they don't understand why anything actually works. How boring that would be...
Devon