I do have EQ 7 and love it.
I did just look at the link you put on here and according to eBay, that listing has been removed.
It could have been an upgrade. When a new version is coming out, you get an email from EQ asking if you want the upgrade version. That is usually much less than the full version. You do have to be registered as an owner to get this. You may not have been able to to do that with the version that was offered on eBay.
One word about eBay protecting you - it is a BIG hastle to deal with trying to get your money back. Ask me how I know.