Does anybody know a good auction software for charity?

Hi,

I'm a volunteer with a non profit organisation. We're having a charity event coming up. We have gathered several pieces that people have donated which we can put up for sale via an auction where people can bid on. All proceeds go to charity.

I am using wordpress for a couple of months now, and I;m willing to set up this auction site for this charity event. However, the only WP auction plugin I could find is WP auction and it's selling for USD 179. (you need the paid version to put auctions in a WP post). Our organisation cannot afford this, and it's been hard trying to find sponsors nowadays.

Therefore I would like to ask if anyone could suggest an alternative (preferably freen) version of auction software for WP. Or have any other ideas for setting up such site. (we're not US based). The website has to be live by the end of september at the latest. Since I will need all the time to set up the site, I really would appreciate it if anyone could help me out or would guide me in the right direction.

Sorry if this should not be the correct (sub)forum for my question. Please redirect me to the correct one.

Thanks,

Maureen