Did a little quick math. If they paid 40% in taxes, then netted $150,000. Paid $3,000/month in rent, still leaves $112,000. Paid $22,000 during the year for student loans, still leaves $7,500 PER MONTH to spend on subway, off-brand clothes, food, etc. How could 2 people spend that and have nothing to show for it?
Good question.
I also see they are saving for a house. They have saved 3 years, and are 3 years away from having a $100,000 down payment.
That means they are putting $16,666 into savings each year. Or about $1,388 per month.