Hey, I went for the logo under the hammer because of the word "bid" signifying an auction, the text is slightly squished by the logo to signify it being hit and sold, I think it shows what your site is about as soon as its viewed, The colors and design arn't final and .com can be added later if required, the logo is also fully original as you would expect and also fully vector so it will be resizeable to any scale without loosing quality.
All the best,
Phil.