Let's suppose hypothetically that Dez' demands are just too rich for the Cowboys, or that there is some damning info on Dez that hasn't been made public yet. Let's also suppose that the Cowboys' aren't hell bent on keeping Dez like everyone thinks they are.
Instead of even trying to lock up Dez long term they just franchse Dez having no intention of resigning him at all. (I know that goes against conventional wisdom). Personally I'm not sure that it is that far fetched if you consider why would the Cowboys pay top 5 receiver money to someone who they have to baby-sit with full time staff hired by the Cowboys off the field.
In that scenario, Dez would either play under the franchise tag, with Dez bearing all the risk of loss due to injury (other than the remainder of the franchise tag year). So in that case the Cowboys' risk of loss is no worse than the Spencer situation.
If another team were to come in and steal Dez then they would have to come in and pay Dez out the *** and take on Dez (with his baby sitting albatross, and carry the risk of loss due to potential injury to Dez going forward) AND ADDITIONALLY GIVE UP TWO...LET ME REPEAT TWO FIRST ROUND PICKS as the cost of doing business to do it. In doing that the new team gives up two low cost first round players for FIVE YEARS, and takes on Dez' huge cap hit.
So if the Cowboys lost Dez, they could potentially draft a first round receiver with this year's pick AND draft a first round receiver next year as well with the other first round pick, at the low end rookie wage scale.
Let that soak in for a moment......we could sign Suh or any other defensive player we want if Dez bolts for the same cap hit AND still get two first round picks to boot to offset the cost of the free agent signing. Maybe if Dez goes it is not the end of the world after all.
This is one more reason why the Cowboys have all the leverage in these negotiations.