AZ PACU Contract plus Call

Personally, I would not touch any assignment that paid less than $50 an hour in total compensation per PanTravelers Calculator. I suspect putting in your assignment details will result in about $42 an hour total compensation (including employer's share of payroll taxes).

The even more egregious part of your proposed contract is overtime (and probably call pay as well). Accept no less than $63 an hour. Even at this rate, the agency will be making out like a bandit. If the bill rate is between $60 and $70 an hour (almost certainly) and time and a half is paid on that rate (about 70% probability) then the agency is being paid $90 to $105 per hour.

The lowest amount the agency will bill for OT is base rate plus $10. So even there, they can afford to pay the rate I mentioned above. They can do no worse than break even at that rate, and already have negotiated a profit margin for the entire assignment that they deem fair (to lucrative). No reason they should earn more for your extra work.

Also, you have a significant risk factor as you might get struck by Covid. Pretty hard to determine what that risk is worth, but some agencies are paying 2-4 weeks if assignment has to be terminated due to getting infected.