> I think this goes against the GNU Public License.

Not clearly. Selling GPL software is perfectly legal, as 
long as you leave the license unspoiled and provide the way 
to download the sources. This is the biggest probleme here: 
no reference to the license in the selling page, nor to the 
original program name. (And I don't want to spoil $4 to 
check that)

Ebay Recordable Media policy is not very clear:
<http://pages.ebay.com/help/policies/recordable.html>

"The following are examples of items that may not be listed 
on eBay:
(..)
Compilation of 500 "freeware" and "shareware" programs on 
one CD-R 
"

Nothing is said about GPL programs. I guess the Ebay's 
strategy is not to offend big players (Adobe, MS), but in 
the other hand they just don't give a damn about people 
selling "free" material, even without telling it.