I generally dislike kiais. 5 seconds is ok, more than that is pushing it. I wouldn't mind as much if it was only buyable for real money, because far fewer people buy things with real money, no matter the amount.
I'd rather give special features to someone who has helped the community than to some farmer.
Kiais aren't really meant to be music (*ahem* dubstep), they're meant to be a short opening shout. If I was in charge, I'd lower the "basic" version to three seconds max.
Just my thoughts.