It is all from boosters, and there are plenty of them that won't pony up more while KS is there. I do believe they will pony up to keep Hill.
Look at the difference in what the basketball program is doing, that isn't coming from BYU they will never spend like that. That is all coming from boosters that are willing to pay now that KY is the hc.
KS hasn't shown he will make the changes or do what is necessary for those boosters to put the $$ in the program. The only thing they were willing to do was pay Hill, and I feel confident they will pay to keep him.
But KS's love affair with his best buddy for way too long at DC proved to those with the $$ that they don't trust him and in turn they won't invest like they have for Young.