Dak and Hurts are similar? Let's see...
In the same amount of time that Hurts has been in the league:
Games Played % - Pass Yds/Game - Passing TDs/Game - Pass Comp % - Passer Rate
Hurts: 88.24 - 228.17 - 1.27 - 63.93 - 94.37
Dak: 65.63 - 321.81 - 1.86 - 66.56 - 99.66
https://www.spotrac.com/nfl/philadelphia-eagles/jalen-hurts-47648/market-value/
Now let's add Kyler Murray and Josh Allen...
Murray: 90.91 - 258.6 - 1.67 - 68.22 - 97.43
Allen: 100.0 - 238.53 - 1.78 - 64.01 - 96.24
As QB passers, Dak and Hurts are not similar. Dak is a better passer. Dak is an even better passer than Kyler Murray and Josh Allen as well, yet they are paid higher than Dak (see contract numbers below)...
Contracts comparison:
Length - Value - Avg. Salary - Age when signed
Murray: 5 - $230,500,000 - $46,100,000 - 24
Allen: 6 - $258,034,000 - $43,005,667 - 25
Dak: 4 - $160,000,000 - $40,000,000 - 27
As you can see, Dak is the lesser paid of all 3 QBs, yet he's the better passer. Hurts is due a new contract. He's estimated to get a new contract averaging around $44.25 million/year. Based on the average pay/year Murray and Allen are getting paid, Hurts will likely end up getting paid higher than his estimated value of $44.25 mil/year.
So, as one can see, Dak's $40 mil/year is much cheaper than what Murray and Allen are getting paid...and what Hurts is about to get paid. All while Dak is the better passer than all QBs in comparison. The QB market is what it is, and it's not going to change anytime soon. Looks like the Cowboys got the better end of the stick compared to the other QBs mentioned.