Yeah, that's about what they take from us travelers, usually. Sometimes less.
Have a news article.
Not that I really care tbh. The hospital I was staff at paid me 35/hr, refused us additional pay for being short staffed, and gave us 1 N95 "for the duration" (until it broke) and garbed us in trash bags so they could give the CEO a multimillion dollar bonus. Screw 'em, pay me. It's nice to have leverage for once, as ephemeral as it is. If the agencies didn't have things sewed up I'd form my own LLC to negotiate for the bill rate as my own agency. Save them some money and fill my own pockets.
Maybe we're talking about different situations, but I've worked a good dozen contracts for multiple companies and nobody has ever charged me up front.