I'm in agreement with
LarryJ. WN pilots can indeed earn $250k. Average top pay for a WN pilot is about $150k.
The difference between WN and the other majors is that WN pilots actually have to fly a lot more hours to get that pay - in other words, WN pilots deliver superior productivity over any other major carrier. In 2001, on average, WN pilots flew 62 hours per month, while UA's pilots flew 36 hours per month.

WN pilots who average 80 per month (thus maxing out the 1000 allowed annually by the FAA) can earn the $250k.
See page 58 of 82 (internal page 54) for avg flight hours
WN gets a lot of productivity out of all their employees, not just pilots. Just because their costs are lower doesn't necessarily mean their hourly pay rates are lower. WN has far fewer employees per passenger mile than most carriers.
We disagree as to whether the full-service international route majors (UA and AA in particular) can operate their route structure and get their pilots flying more like 60-70 hours per month instead of 36 and 39, respectively. I say it's doable but
LarryJ has in the past disagreed.