Go to the dollar store and buy multiple items like scented candles, neat picture frames, wind chimes etc... things you think your group might like. In addition to this you can ask everyone to bring a small item for the auction. $5 limit is good. After the solution is read you can start the auction & let people bid on these items using the game money that they have managed to acquire during the game.
Here is what happened when we did this: People with good winnings bought the things they wanted and then people gave some of their money to those who didn't have any or very little money so that they could buy items too. People got into bidding wars and were paying $500 for an item
Everyone left with a neat momento of the evening!
Our group are pretty selfless so if you have some guests that may try to hog everything it is a good idea to make an announcement before the auction that the point of the auction is to allow everyone to leave with an item, so if anyone has excessive winnings they are encouraged to share with those less fortunate.
