The price they quoted was for a disc with a valid license. His discs didn't have licenses, so they were worth a few cents apiece.
That is where you're wrong. Read the docket, better yet here is a screenshot from the demonstration that the discs had keys replicated from original Dell recovery discs:
Moreover, "so they were worth a few cents apiece." - The value of financial damage (especially in this case) matters only towards deciding the restitution amount. They also have a cut-off, above which the crime is considered to be under federal jurisdiction which wouldn't have mattered in this case since the amount was obviously above the cut-off and the crime was of inter-state nature.
However, in this case you wouldn't see "Contact Dell for Support" on a lenovo laptop as demonstrated during the trial (see screenshot above).
If the disk had no activation info, setup would have prompted for a key (trial keys for 30 day are available online).
Big OEMs including Dell and Lenovo use an activation baked into the BIOS and a SLIC (system licence internal code) that's also in the BIOS. No activation required after restore from legitimate or otherwise CD or restore partition. It won't match the code on the machine's sticker, even if it's 100% legit just bought new from maker.
Search will turn up plenty on how SLIC works.