At this point, I don't think Marg would care much for the $$$ because she has earned what I will never get my entire life in the past eight years, and even if she left the show, she'd still earn from the residues from the reruns of CSI and the sold CSI merchandises. I think she's more concerned about Catherine's character development. We all know that she was considering leaving the show in early season 7. After Billy's intention was revealed to the cast and the crew, though, I think she probably saw a chance for Catherine after Grissom's departure. Plus I'm pretty sure that TPTB must have given her a raise to keep her since she will be the only "star" of the show. However, if there was only a raise and no talks about good plots for Catherine, I doubt she would renew her contract.