Teacher Discussion Forums

Hi I'm a newbie at teaching EFL and found an interesting lesson plan I would like to use. It's called a "sentence auction" and details can be found at:

http://esl.about.com/library/lessons/bl_auction3.htm

I'm stuck trying to think of a good warm up exercise/ice breaker that teaches the concept of an auction. I'm not looking for anything too complex, something remotely related will do. If anyone has any suggestions I would very much appreciate them. Thanks in advance.

Any chance your students will have heard of eBay? Start a discussion about that, do they know it? Have any of them used it? Did they buy something or sell something? What was the object of trade? Etc etc. That will lead naturally into the grammar auction.