Version 3 is better in my personal opinion.
A few things to make it have better usability for the buyer: automatically fit the image to the screen, rather than have a view full size button. Change that button to a zoom feature. This will allow the visitor to zoom in on the image if needed which probably wont happen too often because this image is more viewable but if it needed its there. Also, most image galleries stack the images from 1 down to say 6 before starting the second column of images for fast scanning, you can write the code to allow for centering of images until a 7th image is detected and then reset code to allow for double column. The end user will not see this happen it will load before they do.
I do think the color palette is nice but solitarysandpiper is right and that is why most galleries are still built with white backgrounds. To give it a more modern look you could create a frame appearance with a black/dark gray outer frame while still leaving the area around the image white, similar to thedouble matting of a painting you could even give the appearance of a beveled edge on the outer layer. If you stay with it as it is now it would be better to lighten the background on the left column so each images is clearly distinguishable from the background, and set the background for the large view to black for the background/border and allow auctiva users/sellers to have to option to change it if needed.
I think it is great that you put things out there for feedback from your users so that the end users of our listings get a better product.