It's actually almost absurd of me to complain too much about the price, given the Lego sets I already own (a freaking
Helicarrier!?), but yeah, when I consider it versus just implementing things with a simpler board (I was considering something like a Teensy would be enough for many simpler programs), and I'm sure others have though of, and likely done, the same.
Might be something to look for on Youtube at some point. the only show I regularly watch that does anything similar is Ben Heck, and I don't think he does Lego at all, but I'm sure there are others out there. And while a simple "Ultimate Machine" is easy enough, one that can retract it's switch, dodge an incoming hand, and so on is a bit more complex than that.
(Although, being an engineer, my brain *immediately* began thinking of how I could use parts around my house to do this, what else I'd need, and so on. a few sensors, a toggle, a few motors? Sounds kinda simple in practice.)