I think @Brook_Drumm would be happy… I just helped a friend resurrect an old Printrbot Simple Metal in order to teach 10-12 year olds how to design and print.
The inductive sensor wasn’t working, but I discovered that it would reliably trigger from 5V even though it was labeled 6-36V, and so simply moving the power supply for the sensor from “HV” to “5V” got it working again. It’s clearly a solid little machine, and will be ready for teaching next week. 
Printrbot was an amazing story. Brook Drumm had some great ideas. It is a shame that he was unable to keep up with the cheap Chinese printers. I was very interested in his 4 x 8 plywood CNC crawler that never went into production.
Very close. It was called printrbot Crawlbot Cnc router. The comments do mention that it actually did go on sale but I am not sure how many were actually sold. I found a video of it on YouTube.
Huh, on Twitter he says printrbot is coming back this year. He shows a gantry-style bed-flinger, but still with the same hot end used on the classic printrbots and with an inductive Z endstop. I’d expect solid mechanics, but I wonder why not updating the hot end to a more recent design?
Cheaper to start up operations.
Given that Ubis has been making new ones to sell to printrbot owners at $50-$70 each, I doubt there’s a massive pile of NOS to get rid of. And newer designs are also available cheaper. I’m guessing he just likes them. But I have no special knowledge here.
Brook has a Patreon to which people have been contributing to help him through the rough patch since the Printrbot closure:
https://www.patreon.com/brookdrumm/posts
His Patron only posts there give details for what he’s working on next, upcoming stuff, etc.