Way to much deadspace at the top of the page. I understand that the space is necessary in the rest of the site to showcase videos and pics, but maybe put some graphics or something next to your logo.
Centering the layout would be great too. In the ol widescreen, you have a ton of dead space on the right side ( my res is at 1200 so I am a little out there I know)
Is there a way, (humbly speaking here) that your landing page for purchasing the videos could reflect more of the original site? Once you click on a video, the purchase page has nothing that ties it to the original site, I would worry about jumping from your site to the other url without something to reassure the shopper that you are still with them ( specially since you redirect out of the site for purchasing)
and your actual purchase page has some way bitty looking logos for the visa and mastercard logo ( definately build your customers trust with you if they are plunking a CC number with you)
I did also notice too, that when I went to fill out the order form, I place Alaska as the state to deliver to, with my zip code from Washington state. And then the other way around and the shipping cost did not change. Perhaps changing the wording on the button to "order now" instead of "calculate shipping"?
Hope this helps..