Game Ball

This may seem mundane, well it is, but at least it's not another Tate/Denard thread. I noticed during the spring game and fall practice this year that Michigan is using a different ball from years past. Whereas before they would use Wilson 1001, it seems that they are now using the Wilson GST. I was under the impression that the 1001s were really high quality and retailed for around 100 dollars, whereas I've seen GSTs in regular sporting good stores for a much cheaper price. Can anyone shed any light on this?