There are not 10 QBs in the nfl that even average 24m$ a year, as each guy who signed ~25 million a year still had a year left on their deal. Ergo, your logic must be applied to all and he does still land in the top 10
For how long? The last several QB contracts all reset the market.
- 2011 - P.Manning - 5 years, $90M - avg 18M per season
- 2012 - P.Manning - 5 years, $96M - avg 19.2M per season
- 2012 - Brees - 5 years, $100M - avg $20M per season
- 2013 - Flacco - 6 years, $120.6M - avg $20.6M per season
- 2013 - Ryan - 5 years, $103.75M - avg $20.75M per season
- 2013 - Rodgers - 5 years, $110M - avg $22M per season
- 2016 - Flacco - 4 year, $66.4M - avg 22.13M per season
- 2016 - Luck - 6 years, $140M - avg $23.3M per season
- 2017 - Cousins - 1 year, $23.9M - avg. $23.9M per season
- 2017 - Stafford - 5 years, $135M - avg $27M per season
- 2018 - Garoppolo - 5 years, $137.5M - avg 27.5M per season
- 2018 - Ryan - 5 years, $150M - avg $30M per season
- 2018 - Rodgers - 4 years, $132M - avg $33M per season
- 2019 - Wilson - 5 years, $175M - avg $35M per season
After Wilson signed this year, Roestlibergers signed a 2 year deal for $68M, avg $34M per year.
Dak Prescott may technically get a 6 year, $30M extension for seasons 2020-2025. But with his 2019 $2M salary, that is $182M over 7 years, an average of $26M per season. That is less than 75% of the $35M per season that Wilson will make. While he might be near the top of the scale temporarily, he'll be quickly surpassed by deals for Goff, Wentz, and Cam Newton next year. Phenom Mahomes, DeShaun Watson, and Mitch Trubisky to will pass Dak by two years from now.
By the 2021 season, Dak Prescott's average of $26M per season over 7 years will be exceeded by Russell Wilson, Ben Roethlisberger, Aaron Rodgers, Matt Ryan, Jimmy Garoppolo, Matthew Stafford, Jared Goff, Carson Wentz, Cam Newton, Patrick Mahomes, DeShaun Watson, and Mitch Trubisky, making him the 13th highest paid QB in the NFL. And if the Cowboys get him for $28.5M per season, his actual average over 7 years will be under $25M per season. At the same time, over the next 7 years, the NFL expects the Salary CAP to increase at least $70-80M, meaning that the it will go up to about $260M-$270M per year. A deal where the starting franchise QB makes 10% or less of the overall CAP is a great deal for the Cowboys.
If you think Prescott is a slightly better than average, but not elite QB, then a 6 year contract extension paying him $168-180M from 2020-2025 is just about the right amount.