Ummm do you know what
SEO is? That's the whole point of duplication. You always repeat your keyphrase in your title tag as well as numerous times on the page. Of course there isn't much text, this is a sales site not a content site. I want people to click off to set the cookie. The nav links all say discount to rank well for discount categories. However the page itself is clearly about costumes. The title reflects this, the metas, and the content of the page are all costumes. Not sure why you're not seeing a heading as I see one that says Buy Halloween Costumes. Not sure what you mean to infer on the php comment as this has no bearing on the ranking of a page, Google indexes php fine.
The link partners you are prolly seeing are the ones that add you to their sites with no permission. I get these scraper sites all the time linking to me. There are a few legitimate sites of course, largely my ten other sites plus others who have similar sales sites.