The Southwest monthly guarantee is 79 hours per month (948 hours/yr), first year FO pay is $52/hr, and the FAA max flight time is 1000 hours.

So, between $48K and $52K is a pretty reasonable estimate.

Your right that payscales don't tell the whole story - but planning finances on the low end of the spectrum is never a bad policy - everything above will be a "windfall".