Dracos, pray tell, where do you hail from? I'd like to check out this Target store of yours.
Target is a planned-space environment. While it makes for really nice, neat display cases (as opposed to say, Kmart or some Wal-Marts with haphazard stacks of games), it also means that once a game falls below a certain sell-through amount, it will be rapidly marked down until gone to make room for a game that will sell better. Then wash, rinse, repeat. That's what happened to Disgaea, and I would be surprised if there were more than a handful of copies left in the whole chain, because once that mark-down process happens, they're not bringing the title back in. It does make for some killer deals though, if you time your visit just right.