Got a mate ex Hong Kong with National got his command after the 1000hrs FAA (18 months). Like most of the US carriers you can work as hard or as little as you desire because their rosters allow for lifestyle or cash.
I’d say the 420k for a year is easily doable but it might mean working absolutely flat out one month and then backing off the next to average 4 wks off over 2 month's. I know for a fact he raked in 70k for a month but it was flat out and the tax did some damage, but he’s now exploring ways to put some balance to his life and reduce his tax. The point is he has control of his life and earnings and everyone wants something different which usually means less complaining.