I don't quite understand this.
A 5 day/10 gig account on a 600-day-retention server seems suspiciously like a trial account on Usenet.net or Powerusenet, since that is exactly what they offer for their trial accounts.
It used to be that the trial account there could be aquired without having to input a valid credit card number - but I don't know for certain if it is still that way today.
Personally, I think I'd prefer the free trials at Hitnews/Xennews, since they don't limit the trial to just 10 gigs download.
I used to use free trials a lot when I was first starting out with usenet, but I now prefer to pay my way since I became a regular newsgroupie.
But for anyone who can't spare a few bucks, and doesn't mind taking the time to sign up for a new trial account every few days, I guess you could leech off trial accounts virtually forever if you really wanted to.