Relocation fee is chief among these. Can't forget the NBA debt as well. Plus you have to factor in the other associated costs of the move (AKA severing sponsorships, etc.)
Well to keep it real, they would be creating new sponsorships in Seattle, and probably more lucrative.
The loan to the city is $64 million with $14 million in interest, so $77 million to the city. It's a loan, they could very well pay off that loan with a loan... so to count that as a $77 million "discount" as others seem to be doing isn't correct.
There's the issue of the $150-219 million the team owes the NBA, but that's likely paid off from what the Maloofs get from the sale.
So the real discount comes down to the $30 minimum relocation fee. That's still a hefty discount for keeping the Kings in Sacramento. We'll see how it plays out. The people with the deepest pockets don't always win.. or Larry Ellison would own the Warriors right now..