I have to agree with gaff, you can't survive, even as a college
theatre without charging for tickets. The people who come to the theatre will still come, even if it costs $5. The IC theatre department gave every department student a comp to each show, because most classes required you to see the shows, and if you work on or are in a show you got two comps, everyone else had to come
ups with a whopping $7, I don't think there are many who can't afford that.
We also used to do things like hold auctions. People would put almost anything up for auction from furniture and household goods to notes from classes (the profs did not have any issue with this). All proceeds would go to the department. We would do things like have massage days, where people would volunteer to give massages for something like $5. This worked best during finals weeks.
So there are a couple ideas for you.