Here's another post from the same site I referenced in the previous post. This one advocates a middle ground between big prizes like the X PRIZEs and Centennial Challenges and the smaller ones like some of the student competitions. In the aerospace world even the well-off university and large private teams are tiny in comparision with government projects, so in a sense these "big" ones are really "small", but I see what he means and I do agree that there's a "middle ground" in the prize world that could be filled.
Of course, the "Google Android" software challenge I posted about yesterday could be a "middle ground" prize that a lot of small but very serious and hard working teams could win ...