Han Solo is a good idea. White shirt, vest, khakis, boots, gun. Maybe a cheap teddie bear for amusement.
Zathras, not a huge amount of time money or effort, but I'd like it to be good. At a convention you could wear a costume for a day or even three, but in this case the party is a few hours and then I'll never need this again. On the other hand, the winner by popular vote gets a bottle of hooch.
The year the theme was pirates saw some great, imaginative costumes, and actually the winners were ghost pirates, close enough to zombie pirates. For Cowboy year the winner was the "Electric Cowboy." He strung ordinary cowboy garb with Christmas lights. Last year the theme was "Castaways" which basically leaves Tom Hanks or a member of the Gilligan's Island crew. The winner was an unimaginative but well-executed Gilligan.
This is a convention of manufacturers. There is one guy I know who is a Star Wars fan, but other than that they are not geeks. Zombie Han Solo or Zombie Spock are great ideas (actually, zombie Spock is the funniest thing I've heard in a long time), but I need to go pretty conventional.
Now that I think of it, the Star Wars guy might go as someone from his world. All the more reason for me to go Spock.
Where do I get ears and a wig?