I worked for a firm that made PCB processing machines out of welded plastic sheet. All sorts of items were fabricated in-house including bookshelves and the like. Typically the cost would be several times higher than it would have been to buy the items but of course the costs were "lost" rather than requiring approval.
On the other hand when I worked for a metal framing company we had a whole room full of bolted together bookcases that needed clearing - I'm still building racking for sheds, etc. out of the stuff having brought it home in small batches on the roof of the car.