You've got no real evidence to support the idea that higher prices specifically are how credit card companies pay for their perks... All you can say for sure i

You've got no real evidence to support the idea that higher prices specifically are how credit card companies pay for their perks... All you can say for sure is that credit card companies have revenue, and some of that revenue is spent on marketing, such as signup bonuses, and that's pretty obvious. "Company sets prices to account for marketing budget" is hardly a revelation.