We would love to find a large backer for bigger prizes. If we are being honest the potential for 1 SBI isn't a huge motivator to most people. Those who come week in and week out are doing this because they want to help give exposure to others and the prizes they pick up along the way are a bonus.
One of my goals is to get the reward pool increased and remove the financial burden from all of the judges. They each buy an SBI share plus do a ton of work. In return one sponsor buys each judge an SBI share which is great so the judges end up with 2 each week helping their long term growth.