It's pretty common if you have IT and finance teams that are paying attention. Sure a lot of shops let them waste away on a shelf, but that's what it is, waste. If you have fungible inventory that isn't likely to get used soon it is just a mistake it let it sit around unutilized. If it is cash, it is easier to utilize on other projects.

Ours are on lease, but the leasing company will release some from time to time for auctions at $DAYJOB. I've won 2. Using one, son flipped the other one for a couple hundred dollar profit.

Every laptop I've ever purchased was corporate surplus

Apple has a buyback program for corporations.