The Timmy Jernigan example makes every bit of from the market value standpoint. The Akiem Hicks deal made less than 2 months ago set the market considering that Jernigan netted the exact same years and figures. In my eyes, Jernigan's played unquestionable better on tape in Philadelphia, which serves his skill-set better, even by his own admission. It's impressive in its own right considering that the adjustment period of switching from being a leverage-based two-gapping end to a one-gapping tackle in an attacking scheme is arguably one of the biggest changes in mindset for among all interior linemen. That aside, Jernigan has spent most of his snaps at either 3T and RE this season, with and without Fletcher Cox on the field. That's the money position on the interior in a four man front.
While, he's played well in both facets at a position that is paid handsomely, he isn't nearly on the same level in the pass rushing facet as the premier players i.e. Aaron Donald, Gerald McCoy, Kawann Short and even Cox, who manned the RDT role when signing his deal $102.6 million. The only elite 3T whose deal was significantly more affordable was Geno Atkins, who signed his contract after the ACL tear with question marks looming. With Donald expected to be among the league's highest paid players, that group's contracts averages more than $17 million per season. So overall, $5 million less per year for a player of a somewhat lesser caliber who just turned 25 and has seen snaps at literally every single defensive line position aside from the wide-nine DE spots is sensible. Now I'm by no means stating that the deal is guaranteed to prove its value moving forward. Only time will tell and he could vastly disappoint moving forward. But as it stands, with respect to the context of his situation, a Hicks-level contract is hardly unjustifiable.
On the subject of context, it's not overly surprising that Jernigan received a slightly higher average than Williams. The Williams scenario involved a hopeful projection considering that he was paid for a future full-time position that he significantly struggled at in part-time; thereafter, he was given a contract that was directly correlated to more snaps at said position. In Jernigan's case, he was extended several weeks after having one of his best games in Cox's absence, so there was far less projection required, if any. Not to mention that he's younger than Williams by almost the same span as the length of his contract, that being 4 years. So with everything in mind, it'd be weird to laud the contract given to Williams and balk at the contract given to Jernigan.