There isn�??t a way to use a script evaluator to get cost attribute values at a certain time, unfortunately. However, the results of your analysis won�??t change by scaling travel times by a constant value. So could you solve you problem without scaling? For instance, if you don't want people to spend more than $10 on travel costs getting to your facilities, you could convert that to a travel time and put the value as the impedance cutoff, then solve.
If that doesn't work for you, there are two other options: write a custom evaluator or use a scaled-cost polygon barrier. The recommended way is writing a custom evaluator, which is capable of getting what you want, but this may take some time to set up if you�??re not familiar with how to do it.
The other option is to create a scaled cost polygon barrier that covers your network, set the Attr_TravelTime field to your wage value, then solve using TravelTime as the impedance. This would work on a small network but it would take a long time to load and solve on a larger network.
Thanks,
Robert