You need to show me the Kings players you're talking about because I don't see any contracts in capgeek that I'd consider a hometown discount. Stoll, Williams, those aren't discounts. Quick? His contract is cap friendlier but not a discount at all... Doughty certainly wasn't a discount, Voynov didn't take a discount unless you're comparing salaries in the KHL, which doesn't have a cap. And certainly no other team's UFAs have been willing to give the Kings a discount. Scuderi wasn't a discount, Mitchell never signed for less....and neither B. Richards & Kovalchuk were willing to play in L.A. for less money. So I don't know what you're talking about.
I've yet to see the Kings player sign for less than they were worth to stay.