In California, the minimum wage for a film crew is $8/hour. $112 for a 12 hour day, or for a script supervisor you add a wrap hour and it comes out to $128/day MINIMUM. And this is just wages for a low budget film’s Production Assistant, who is at the “bottom” of the pay line. A person serving fries at McDonalds with no high school degree makes this much money.
Continuity script supervisors are a highly trained profession, and are considered department heads. They have numerous responsibilities, save the production time and money, and undoubtedly elevate the quality of the final result. A continuity script supervisor should be paid the same as any other department head.
Hiring a talented non-union crew should warrant a payment between $300-$400 a day, and no lower than $200. Certainly not lower than $150 a day. And while $100 a day seems generous for some low budgets to offer these days, it simply is not meeting legal minimum wage requirements.
Myself, I also work digitally, using high tech equipment, and like to be sure that a company has insurance to cover damages and losses. I also prefer to negotiate a kit rental fee for the use of my equipment, as any camera person or sound person would.
In summary, I think a fair rate for a continuity script supervisor (who really knows their shit and has excellent references) should be between $200-400 a day, depending on if paper/pencil is used, or digital, and the type of kit fee that is negotiated