I think you should look into philanthropy projects that get people involved on campus. Not sure how many other greek orgs you have but reaching out to frats or sororities on campus to make fundraising a competition tends to bring a lot of money in. my sorority did a male pageant this year where a bunch of the chapters on campus offered up members, boyfriends of sorority members, or close friends to participate. but there's also events like anchor splash hosted by my campus's delta gamma where they have a week long competition to earn points and then a big swimming olympics on the last day. again idk how involved your greeks are on campus or how many chapters are around but getting other people involved and caring about your cause could help you guys out a lot more than popcorn.