Only shock is the guaranteed. That's a ton.
Guaranteed works out to just over $21 million per year. That's the number we need to be paying attention to.
Let's say almost half of the guarantee is signing bonus. That's $10 million per year, so Dallas would need to pay $56 million in other base or bonuses over four years to fulfill the guarantee. Essentially that means that Dallas would pay Dak $96 million of his total guarantee over four years, with the final $10 million in bonus prorated for the fifth year when his base will likely exceed his bonus either leading to a renegotiation or him being cut.
Usually, the contract escalates as well so that it can be restructured if needed. So it might look something like this:
$5 million base, $10 million bonus for $15 million in 2020.
$12 million base, $10 million bonus for $22 million in 2021.
$14 million base, $10 million bonus for $24 million in 2022.
$25 million base, $10 million bonus for $35 million in 2023. (This would be the ideal year to restructure or renegotiate because of the jump in base pay.)
Remaining base salary, $10 million bonus in 2024. (If Dallas didn't renegotiate in 2023, this would be either the opt out year since the base exceeds the guarantee or the year the team would absolutely have to renegotiate.)
In comparison, Wentz got almost $108 million guaranteed when he renegotiated his deal. He'll make $18.6 million this year and $34,6 next year (after making $8.3 last year) before Philly can option out. If the Eagles opt out that year they will be hit by $24.5 million in dead money, but will save nearly $7 million in cap space.
This is why Dallas needs a fifth year with Prescott. It allows that guaranteed hit to be extended into an extra year to lower the hits for the first four.