I don't think it is perceived value. If someone was messing around charging $450-$1000 per hour, they wouldn't last two seconds and their clients would make sure of that. It is about ROI and trust. Would you trust someone charging $50-$100 per hour on UpWork to fix your ten million dollar problem? I wouldn't. You probably wouldn't either. It's just too risky. I find that bigger clients want their risks to be mitigated. They don't want to gamble on people. They want to invest in people.