Sellers have been asking me for more mobile-friendly templates - and it's been a trick to get something to look good on a monitor, tablet & phone since eBay doesn't allow us to add CSS for mobile. This is a layout I've been going to so it looks nice on a monitor while the description text appears right away on a phone: http://www.ebay.com/itm/171053400692. (Getting away from a header on the template and using a "right/top sider"...)
Your example layout seems to assume either the shopper is using a computer (in which case the full item description images, text, and styling appears) or a device to which eBay redirects to the version of the item listing that displays the item description text only with minimal HTML formatting.
There's a very significant third possibility the listing will be visited using a smart phone in which case eBay directs to a version of the listing that will display the item description fully rendered. To accommodate that version ideally the block content should scale to the viewport (window size) of the phone so all or at least most of the layout width initially appears. Typically a smart phone will allow pinching to expand or contract the overall contents so getting it ALL to fit initially isn't critical. Your example is locked to an overall width of 1122 pixels which is a few hundred pixels too wide for that initial view. 940 would be better. Here's a simple layout that accommodates all three possibilities:
Notice how it contracts to smaller widths when viewed in a narrower window.
Hope this helps,