A bit of background information on this award. As a business student
and as President of the 2004 SoCal Entrepreneurship Award winning team, *avoids all the rocks that the engineering students are currently heaving in my direction at this current time period* and as a dedicated FIRST-er, I have had first-hand experience integrating the unique pressures that FIRST can bring toward a team in both a competition and a preparation for competition setting.
No matter how many sponsors a team has, they must always be on the lookout, or should always be on the lookout for new ones (unless they are entered into an exclusive agreement). With each search for a sponsor, the process should be documented so that a template can be followed for the future. This template should be explained to the Judges when they come around to interview by a knowledgeable student.
Secondly, grassroots fund raising not only brings in extra income, it demonstrates a vested interest and effort on the part of the team to raise awareness within the community, something that is also a requirement of the Chairman's award. For the past 3 years, our team has successfully been selling freezies and samosas above cost at our high school right after the last period of the day. The only thing to be concerned about here is supply and any production agreements with your cafeteria (try to work around them!)
A business plan is a demonstrated need for any team to have, but it is not necessary to flaunt it as the main idea behind your efforts to win the award. Instead, focus on a holistic, Chairman's style approach that underlines all the efforts your team has made to spread awareness, whether for fund raising or not within your community in terms of local and corporate levels. For example, ours was still under development when we traveled to SoCal.
The interview with the judges is critical but ensure you have a student speaking, without making it seem scripted or contrite in any way. Demonstrate a real passion for one of the most overlooked aspects of FIRST and you will have your way.