Sounds like this guy made a really bad decision in putting the Windows and Dell logos on the disks, and then selling them (albeit for $0.25, which would seem to just barely cover the cost of production.) But that bad decision pales in comparison to the court's decision to value at $25 what Microsoft was giving away for free. If anything, he was saving them a significant amount of bandwidth.
Microsoft wasn't giving them away for free though. According to the article, they get $25 for each disk from computer manufacturers.
So the $25 is the cost, to Dell etc, of volume purchase of Windows OEM along with the sticker with licence number.
Utterly unrelated to a restore disk for a machine that already has the sticker, and thus a valid licence.
That he is found guilty is a travesty.