If tickets are only $75, than a tuxedo is way overboard. I think a nice suit; depending on the crowd you expect you may get away with bizz casual.
You don't want to do jeans, and t-shirts, but you could probably do button down, slacks, and shoes + jewelry.. watch, wallet, whatever you carry.
I am not envisioning the quirky costumes of, "angus young, risky business, revenge of the nerds, and madonna," being a big hit. But maybe that's just me... don't get me wrong though, I am sure the party will be themed that way, doesn't mean the guests will be dressed that way... unless... "did it say to on the invites?"