if I'm not mistaken our wage bill pre Ronaldo was actually lower than the likes of Liverpool for example. We should be capable of paying big money for Casemiro when you consider we have let go of a lot of big wage stars and will likely let go of Ronaldo on top.
Casemiro isn't a Rabiot Christmas stocking player, he would be part of a spine for Ten Hag that is absolutely integral for the system. I think Martinez - Casemiro - Eriksen is a fantastic vertical spine, just need the striker but that can wait for now.