I stocked up on a few when TRU had em for 4.99 on clearance..this was several months ago, possibly a year. However you may get lucky finding some still there.
They probably are. The two TRU stores I got are clearing out all of their DC stock with one of those 'bin sales'. I seen a lot of common DC games but no controller though.
I'm just waiting for Gamestop to add another 20-30% off on their DC selections!!
One of my local Gamestop's had a BUNCH of controllers just sitting in bins, not sure if they're still there, though. I think they were like 5 dollars or something. Not sure, it was a while back. Sorry if that didn't help.