Remember that TBBT was sold to syndication in 2010 for $2+ million per episode. It’s been the top rated comedy in syndication ever since, and some weeks it’s number one overall with 10 million viewers. Every season going forward is additional money into a bottomless piggy bank, since that’s $2+ million in addition to whatever CBS is paying per episode.
Raising cast salaries is the 429th concern on anyone’s list.
Zazzy! 
(and it was twenty-five cats, not seven. :D)
the number of cats increased during the episode.
“Here’s your cat. And here’s your 20 dollars.” 
Sheldon started with 1 cat, then it was 7, and then it was 25. Or at least, I remember Leonard coughing “25 cats” when Sheldon’s Mother was there.
If you decide to repost that in the right thread, it’s “free REIN,” dammit.
It autocorrected on me.
I hate it when that happens.