Can't believe you are attempting to bribe us dude!
Anyways, a rather simple event we started up last year was a 3 on 3 ultimate frisbee tournament about 2 months prior to spring rush.
We put out an ad in the school newspaper notifying the campus of when it was going to be, set a deadline for entries and talked it up at the bars, within the greek system, our friends, pretty much wherever we could.
After we got the entries totaled 2 interested prospectives would be paired with a brother as their coach and teammate. This allowed the brothers to kind of scope out the guys as well as have them learn about the group on a more informal basis, which is a great way to inform about the fraternity as opposed to sitting them in a room during rush and telling them about the history.
The entry fee was 10 bucks per guy and it went directly to the childrens miracle network. The total only came to around 300 dollars, but this wasn't our main philanthropy event, so it was cool either way.
Material wise, it cost us nothing. Seeing as we are allowed to check out stuff from sports and recreation of the university, we got cones to mark off the scoring zones and likea half dozen frisbees for no cost. The field was free, all we had to do was reserve it. We had some ladies from a few of the sororites referee for us, which is always a nice visual attraction
Overall, we met about 30 new guys and over a dozen of them ended up getting bids. We helped out some kids with the donation and all the brothers had a great time. And it didn't cost a cent!