Qantas Pilots are notorious for quoting the “top right hand corner” number on their payslips, which includes allowances and super. In some industries this would be referred to as your overall “package”. The number below that (gross taxable income) is more representative of your base salary (including overtime or additional hours) and is what appears on your group certificate at the end of the year.
Fair chance the 737 FOs on $300k are quoting the top right hand figure. Still good coin when you take out 10.5% super and say $15k in allowances.