It depends on the original design. We might be able to rework the graphics to speed up the loading, or a slight rework of the page itself.
If the site was designed without the speed of loading considered, it might be cheaper just to start over. I have seen some very poorly designed pages when it comes to speed of loading. We go to great lengths to design our pages so they load as fast as possible.
Email us your URL and we will give you quotes to clean up the code and graphics or to redesign the web page if that would be cheaper.