I stumbled across the Kunio sale just before it ended, but I only got 熱血硬派くにおくんSpecial (the Renegade remake). I just finished it last night, and I really wish I had bought the rest.It's almost impossible to find information on the games anywhere online in English, so I didn't want to buy all of them without knowing how they were, but I regret it now. I just picked up the Famicom and GBA version of River City Ransom a few weeks ago, so I'll have to settle for those or buy the other games full price.
I was actually really confused because the demo for Nekketsu Kouha Kuniokun SP: Rantou Kyousoukyouku has the same icon as Nekketsu Kouha Kuniokun Special, and it looks very similar, so I wasn't sure if it was a different game at first or just an enhanced version (it's a new game on the same engine spread out over a larger area with a new story, lots more stuff to buy, extra polish, and partner characters, as far as I can tell. It also costs twice as much).