NeXT Computer
I saw my first NeXT computer at the UT MicroCenter (campus computer store) in 1990. It was a 25 MHz '040 NeXTcube with a Dimension board, a megapixel color monitor and a 400 dpi laser printer. It was a Unix computer with sophisticated graphics and multimedia. It could send and receive voice emails…provided you knew somebody else with a NeXT. It had this weird DSP "geek port" I wasn't quite sure what I'd do with. It was made from magnesium for goodness sake.
It was amazing! And it was entirely beyond my poor university student means at more than $10,000 without the printer (nearly $20K adjusted dollars at the time of this writing).
Turns out Steve Jobs got to work after he was pushed out of Apple in 1985. And in reliable Steve fashion, he made something beautiful. Something desireable. Heck, I just wanted a Unix computer and he brings me this.
So ~15 years later I'm scouring Goodwill, eBay, local auctions — all my usual places. There are a few here and there, but these entirely obsolete computers are still fetching big money, especially if you must have a cube. Since that time they've even started to appreciate.
I eventually managed to find affordable "black hardware," as the original m68k NeXT computers are called. I bought a couple NeXTstation models, a "pizza box" form factor known simply as "the slab." I have both a NeXTstation Color and a monochrome (2-bit grayscale, actually) NeXTstation. They're both pretty rough and the outside but they still function.
Other exhibits have been retired. I'm keeping these.