I am no legal expert but this section of the document you link to seems to suggest that that what these eBay sellers are doing is clearly not legal.
"The Court points out, however, that if the licence acquired by the first acquirer relates to a greater number of users than he needs, that acquirer is not authorised by the effect of the exhaustion of the distribution right to divide the licence and resell only part of it."
This suggests to me that if someone has legally purchased some form of volume licence then they can re-sell that licence as a a single entity (provided of course that they are no longer using it themselves) but cannot split that licence up and resell parts of it to multiple users as these sellers appear to be doing,