Costco's IT department is not above market rates in the Seattle area fyi.
Costco has a rep for paying their cashiers, food handlers, and stocker teams well, comparatively speaking. Their IT teams are mostly outsourced, like all large companies, and aren't impressive by Seattle rates.
But the context of the conversation is white collar crime, corruption, or unfair practices, and paying significantly above market rate.
Costco is a very egalitarian organization. They pay is flatter across the entire hierarchy. Lower rank people are paid more, higher ranked people are paid less. They are a super ethical organization, I'm a big fan (though they could do better at incentivizing innovation).
It's just not the same pattern as paying gigantic amounts of money to hoard up "CS grads" or lawyers.