Luckily, I've been able to mooch off my roommate and beat the game, Superb-ing all 50 stages and getting Perfects in all but two! (RHYTHM RALLY GRPTHRHTHXX)
I'd definitely pay $30 to own a copy myself, though, especially since my siblings are missing out completely, and think I have incredibly strange taste.
As for the Perfects I have remaining:
- Rhythm Rally II (GRHPTHRHTHSPRTHPTHXX)
- Remix 8 (Rhythm Rally/Ninja Dog kills me 90% of the time - what a surprise!)