Always wanted a HERO ever since seeing ads in the back of the Radio Electronics magazines. Of course price was prohibitive.
But also, in the same way that cabinet art portrayed 80's video games as graphical masterpieces even when the graphics themselves were little more than blocks, perhaps it is the hopefulness in the face of failure to deliver on the promises of the early robots that makes them so charming.
I hope to live long enough that someone looks at a Boston Dynamics littledog and says "oh, look at that old thing. It's so primitive!"
When I wrote the article, I believed it was still produced by the original company. I later learned that while the same company produced the RB5X for about 20 years after its initial release, eventually the name & the remaining stock was sold off, twice.
They kept afloat despite only having produced a handful of bots because the stock of parts was kept in somebody's garage & ever few years when an order came it, the gang got back together to build one.
If you've got an interest in these things & aren't confident about your ability to build one from scratch, the RB5X seems like a good choice: help them clean out their garage. If you are confident in your ability to build one from scratch, I recommend downloading the code, designs, & instructions for the Gemini from Mike Fowler's site -- the Gemini is more capable than even newer robots on the market at a price comparable to what they originally asked for, & the price of components can only have gone down since.
That strikes me as a tough price point to meet. Perhaps I'm jaded after having seen numerous 3-4-5 axis arms on thingiverse & hackaday being 3d-printed and built with servos & stepper motors for a couple hundred bucks or less.