This article pretty much sums it up. This line from the article, in reference to the DE position, "With that group, they probably feel they are covered." This is the problem. The Cowboys front office works to get covered while other teams work to get better. Gregory is not the only player in the league who can play RDE, but he is the best player out of Basham, Armstrong and Golston and it is not close.
This philosophy is not just apparent from the way they handled the DE position, go back to last year and look how they handled the DT position. Urban and Watkins instead of a player who would actually be better than the guys already on the roster.
This is the difference between the Cowboys of today and the Cowboys of the Jimmy Johnson era. Jimmy was always looking to get better. He saw every position as an opportunity to improve and he changed players if he found one better than the guy he already had. Jerry can't seem to grasp the concept of value. Talent and CAP are two completely separate concepts for him. He works the CAP with little regard for talent. Or he signs his talent with little regard for the CAP. The contracts of Zeke, Dak, DLaw and Cooper are examples of the latter.
One more contradiction in the Jones philosophy on free agency. While he insists on building through the draft he often takes big risks in the draft even with high draft picks. He draft Jaylon Smith who had an injury many said would keep him from playing football again. He drafted Randy Gregory who smoked pot before the combine. Jerry took huge risks on these players with 2nd round picks. It seems to me if you are using the draft only to build your team your would look for safer picks who can contribute right away.