I agree the market will probably continue to rise. But every starting quarterback doesn't deserve top end money. Dak is not Mahomes or Aaron Rodgers, not even close. So how close should their contracts be if they all had to sign today?
Besides that, who exactly is Dallas competing with for Prescott? What teams that currently need a starting QB will throw 27 mil per at Dak?
Once again. My point is that IF you want to sign Dak after he's had a very good year, IF he does, the market will be probably $30 mil a year for a "top" quarterback. IF the Cowboys want to pay it, they will do so. And the market will continue to go up, if they don't sign Dak this year for $30 mil, for instance, next year the top may be $31 mil, or $32 mil. So by signing him now, you will save money in the long run. And IF you do so, hopefully he'll earn that contract.
A simple example: In 2017 Stafford signed a 5 year deal for $135 mil, $27 mil average In 2018, one year later, Matt Ryan signed a 5 year deal, for $150 mil, $30 mil a year.
Now of course the team's cap, how willing the quarterback is to sign for a bit less money, guaranteed money and the relative success of the players all comes into play, but again, as a simple example, the salaries go up every year. When Brees came up for a contract a few years ago, he held out until he got either the most total, or most per year or something like that, despite publicly saying the old "hey, it's not the money I just want to win/love it here", but yet, STILL didn't sign until he got that top $$$ figure, whatever it was.
Please note I'm not advocating for any particular action, or amount. Just pointing out that there are reasons and justifications why teams would play a certain amount for a quarterback, or not pay a certain amount, and it's up to the Cowboys to decide what they will do...