First of all, on the subject of Ball:
Halbred, I echo what Mop it up and UncleBob say. If you're investing in Ball as a game to play on the go, I probably wouldn't bother. However, if you would like it as a collectible, then I'd say it's worth picking up (although I still feel that 1200 coins is a little steep). It is definitely a cool recreation of an integral piece of Nintendo history, which is essentially why I ordered it. You will find it to be cooler than the Handheld History cards.
On the subject of Mario Kart: Super Circuit:
I played through MK:SC back when it was first released on the GBA, and at the time, I quite enjoyed it, but it was definitely different from it's predecessors in both controls and course design. I've heard people say that the controls are looser than Super Mario Kart's, and that I will certainly agree with. However, this creates the learning curve that ejamer mentioned. I believe that MK:SC has the biggest learning curve of any Mario Kart game, and many will likely write-off the game too early because of it. Mario Kart is supposed to be quite accessible, after all. On top of the loose steering, you have several courses which require you to make hairpin turns, and arrows flash on the screen to warn you when approaching them. These turns, coupled with the loose controls, require you to memorize the tracks in order to effectively negotiate these turns. It's also therefore likely that you have to memorize the tracks to a degree which you may not have to in other Mario Kart games. I still got plenty of enjoyment out of the game, though.