Chicago Suburbs here. I also worked for Northwestern at their Palos Hospital location. I made 42$/hr base pay for 2 years experience in the OR.
But I moved to agency. I've made anywhere between 50-90$/hr. But sadly there does not seem to be many agency gigs in Illinois right now. So I'm moving back to full time OR, but trying out CVOR this time, so I can go back to agency again eventually.