Trying to get this formula to work and I'm sure it is an easy fix. Help!

Boolean formula help. Here is the formula, I want it to return the result so long as it is greater than the [field rep-minimum fee], otherwise return the minimum fee.

(ToNumber(ToHours([Stop Time]-[Start Time]))*[Field Rep - Hourly Rate]+[Field Rep - Travel Fee])>=[Field Rep - Minimum Rate],<>,"[Field Rep - Minimum Rate]"_