Yes, ironically you see newer FOs with higher net numbers than those who have been in the right seat for 2-3 years. It's got to do with certain tax deductible items (e.g. type rating, cost of living during line training) which have run out by year two or three. Then there are those who cannot accept a reduction in take home pay and start to 'invent' tax deductible expenses, but that's a dangerous path to take. Hence a tax compliant FO a few years down the line looking at around 3000 euro/month.