i'd expect people to have decent luck finding something outside the show on sunday night. because of the paperless thing, if anyone has an extra they couldn't unload it on SH, ebay, or any of the usual outlets. if i was looking i'd ask around a lot and/or make a little sign. be sure to hit up the folks waiting in the GA line. for the two shows that i saw in TX, there were folks in line that had an extra or two but didn't actively sell them b/c they didn't want to look like scalpers, were afraid of being busted, etc.
dunno if you're going to get 50% off, but i'd expect one's chances to be pretty good.