[EricH]

Talk to your current sponsors. Tell them that you may qualify for the World Championships, but will need help to get to St. Louis if you do. Invite them to the MAR Championship to watch. As soon as you qualify, inform them that yes, you did qualify, and ask them to help you get there. (Bonus for telling them a number that you need to raise--registration+travel.) Sometimes it's easier to plan to give extra when you know it could be coming.

Of course, if you don't qualify, then you inform them that unfortunately you did not qualify, and thank them for their sponsorship. (And thank them again later too.)