Yes, to confirm a recruiter's fee is typically anywhere from 15-25% of employee's first year annual salary. So that 150K engineer in NYC earns an independent recruiter (working for herself/himself) anywhere from 22-37K.
Now it's easy to see why some recruiters sometimes act the way they act. People are unlikely to lie just to earn a small fee, but when the numbers get big, the incentive changes.
Now it's easy to see why some recruiters sometimes act the way they act. People are unlikely to lie just to earn a small fee, but when the numbers get big, the incentive changes.