So in 2015 Sitake was offered (by Utah) a 3 yr, $750k/yr job as DC (see https://www.deseret.com/2015/1/9/20555953/in-college-football-assistant-coach-salaries-on-the-rise#utah-defensive-coordinator-kalani-fifita-sitake-at-university-of-utah-football-practice-at-rice-eccles-stadium-tuesday-aug-20-2013-in-salt-lake-city-sitake-has-left-to-become-the-defensive-coordinator-at-oregon-state)

He instead took a 2015 DC job at Oregon St for $730k.  (see https://www.oregonlive.com/beavers/2015/12/kalani_sitake_oregon_state_bea_1.html#:~:text=Sitake's%20annual%20salary%20is%20%24730%2C008,bonuses%2C%20based%20on%20team%20performance.)  

The talk at the time (from what I find now) is that he wanted to keep progressing towards being a HC and thought Anderson and/or the Oregon State job would do a better job of getting him there.

But it doesn't seem like it was an issue of Utah not being willing to pay him enough to keep him.  Maybe it was the 3 year deal?  Or maybe he felt that he needed to prove himself somewhere outside Utah?  Oregon State was (at the time) considered a pretty good spot with Mike Riley doing well enough there to get the Nebraska gig.

And then 2016 Sitake becomes BYU HC for somewhere between $1-$1.5M (according to reports).  Even with Big 12 money, can't see that getting much above maybe $3M, which is still only 60% what you get at USC.