Free Auction Scripts – Open Code to Make Modifications

Hello,
I am looking for a PHP auction script that will allow me to setup a auction site. The site willl need to be able to allow users to be able to create auctions and also be able to setup BUY IT NOW and Reserve Prices.
I am looking for a Free Script (or affordable script) that works and is also not encrypted so I can make modifications to the system if I need to.
I need one that runs really smoothly as well. If anyone knows of any of these please let me know. Thanks again.

See original post by LindseyInteractive