What's the point of them? I've just randomly started collecting them and I wonder if there's some sort of reward for getting them all.

According to the news post here there is a prize for collecting them all, but I'm almost positive that no one actually has yet.

Thanks and I'm not too surprised They're really hard to find if you're trying to buy them. ^_^;

I have spent somewhere around 800-1,000 (estimate, may be a couple hundred off) since they were released.

I have yet to obtain the final 7. They are either very rare or something went wrong in their being released.