I am also considering a daily winner (winning team) for a small amount of points.. That way it makes sense to get involved in the middle of the month sort of thing.

Also, I am a bit worried about having your team expire at the end of each month.. I am thinking about showing the team owner they have XX days left (Buy your team for 30 days). At the end of 30 days, you can re-up. If the team owner does not, then the entire team is disbanded (24-48 hour grace period?)