Should my landing page have the simple (and somewhat cheap) look to it that most do, or should I go with a more attractive site design? Which one will I benefit from more?
I think that cheap look might refer to when people stick with text for the search engines and don't do much in the way of design sincee the engines dont really care how a site looks but more of how it is setup with the text. You are probably designing your lander so people will come back though or take interest in your content, so I think it needs to take the search engines into account but also not look cheap.
depends on the product.. If the product is worth gold, you want to let the product features do the selling and not distract the potential buyers with attractive fluff. If it's a contraversal product which needs credibility to back it up, a nice design will add confidence.
You want to look professional, but the content is what sells the visitor for the most part I reckon...