It's not so much that it's too good to be true. Heck, 10 years ago this kind of thing was fairly common around where I live.
My personal skepticism comes from your original post. the way it reads sounds like something you see in typical marketing stunts on
ebay and the like. And the numbers of dollars and halves you mentioned are so proportional that it makes one think.
As I mentioned before, posting pics of your score will help keep the scrutiny low, if not outright silent.