Seeing this thread in the second page is a little strange.
Anyways, although no other sites mention it at the moment, the actual JP PSN store seems to house an ad that shows Catalogs 3 & 4 are to be up next on the reduced DLC deal starting August 29. These two are the "Kokoro no Marionette" and "CHANGE!!!!" packs; I'm assuming the rates are the same:
Songs: 1800 --> 1500
Extend Outfits: 1500 --> 1050
Stages: 800 --> 580
That's...all I can remember from the first one, sorry. There were plenty more on sale though.