Many teams that host an offseason event use them as fundraisers. If you charge the teams a nominal fee to participate (enough to cover field costs & overhead), you can use concessions as a way to make the team money.
Chris Fultz from 234 wrote a fantastic
white paper about hosting an offseason event - it was our bible for CAGE Match last year. After running our (much) smaller event last fall, we came up with
some tips for event hosting.
Let me know if you have any questions.