Based on the fact that you get 2-3 card gaps in this 150 card set after opening 2 boxes it would appear you need to open three full boxes or so to get the complete set of the 100 vets and 50 rookies. I'm excited because being a set collector and loving the SPX brand (even though they have to use players in college uniforms now) I found a full 50 card set of 2013 Spx at my local dealer that I picked up while grabbing supplies. That will be fun to add to my collection as currently the only 2013 Spx card that I have is the Teo card that's featured at the beginning of my blog.
This is only my 4th Rivers card. Looking at my collection I see that I have not really focused on veterans, most of my cards are rookies and autographs. We know that sometimes these cards hit it big like my 2000 Spx Brian Urlacher but most of them don't. I'd love to see a new football set comprised of all Hall of Famers like a recent baseball release had the guts to do. As long as the company had the proper licensing I think it would be a smash hit.