Yes, yes they do. After you get to deduct your 401(k) contributions, your FSA, your mortgage interest, get deductions for having kids, you don't pay nearly 20-30% of your gross salary in taxes. It's probably closer to 10% when you're at the 100K level, which means you're only nibbling off $3-4,000 of that difference. That leaves about $25K difference per year, or $2K/mo. That's certainly noticeable.