Our High School did a one day hit-a-thon last fall. Players got one swing for each dollar raised...team raised over $13K just from that. I was shocked and I think head coach was too...there were about 40 players involved..so if you have 20...possibly raise half that much as a goal. If you get the money and still have no field then you have an issue though so I'd try to get that lined out in advance before going down a path of fundraising.