Are they company leased computers that are deemed "end of life" and therefore end up on the second hand market? Or have they been resurrected from the dead and now the owner is looking for some return on their investment?

What does "thoroughly checked" mean? Do they just suck the dust out with a vacuum cleaner, check that the fans still go round then put it in a shipping box? If they ship with a Windows operating system is the assumption that it still needs to licensed effectively adding another $190 to the cost?