I can't argue with anything that's been posted above, so I'll just reiterate- it's not how much you earn, it's how much you save/spend.
I used an online compound interest calculator and ran two sets of numbers over ten years at 5% interest:
1) if you invest $48,000/year at 5% interest, you will have roughly $700,000 after ten years.
2) if you invest $36,000/year at 5% interest, you will have roughly $525,000 after ten years.
These numbers are $4,000 and $3,000/month respectively.
If you're an FO with two children in school, it is realistic to achieve either of those savings targets. It just depends on how you choose to live.