A few thoughts:
Your page feels extremely sluggish.
On your site, you have to hover over things to see the prices. That's not good design. On your competitor's site, you're able to quickly scan the page (and use the mouse scrolly to get more items instantly). I see the scrolly does work on your horizontal scrollbar, but it's slow, and counterintuitive. I didn't even think to use the scrolly to move back and forth. Intuitively, the scrolly is a vertical thing.
Key phrase: Form follows function. I would almost certainly not want to buy something from your site because it takes the whole point of ecommerce (find and buy quickly) and replaces it with the brick and morter approach (find something, check the price, set it down, check something else), and does so sluggishly (clicking left and right, or using the little js scrollbar takes like 5-10 seconds to load - way to slow).
Your site looks nice and clean, but that's about it. I wouldn't call it usable at all.
Make it usable, make finding something fast.
Addendum: I think the biggest problem with the usability of your site is the excessive reliance on js animation. My machine isn't exactly old (core2duo, 4gig ram), and it feels like playing a modern FPS game on a netbook.
What's wrong with just using a div with overflow:auto, rather than over-designing it.
Another thought: perhaps allow the bottom part to stretch fill the whole page, so that you can see more items at a time. Perhaps some scale-option to decrease or increase the scale of the pictures allowing more detail and less items perpage, or less detail and more images?