Seeing these always makes me wish there were RPi enclosures that let you build working mini versions of these classic computers. There's something very comfy to me about the idea of playing a text adventure game on a tiny IBM 5100 or HP 85.
If you want something actually nicely injection molded like the PiDPs (which are well worth the price imho, if you're interested in them) I don't know that you're going to find a better deal. I suspect it's too niche a product to scale to being economical at lower prices.