Cool idea.
It seems from the comments you've done this before. So I assume you've worked out the details of what happens in the event of a win.
Are you setting up a trust to claim the prize? Or do you intend to claim the prize as an individual? Have you disclosed who you are in real life? How will we know if you've (i.e. the pool) won anything aside from your word?
(OP, I don't know you at all and I can't recall any interactions we've had - so please don't take this as an attack on your integrity.)
What's to stop you from purchasing drawings independent from the pool - in which case if you won you could claim the entire prize yourself regardless of whether the winning ticket was purchased from pool funds or by you personally?
I guess to put it another way, what safeguards are in place to keep the pool participants from getting screwed?
It's be cool if
@Hornet or
@upNdown could chime in with their legal perspective.