Wtf lol. Where do you live that doesn't have sales tax? This is about income tax. The government gets you coming and going. You made $30,000? I'll take 7. Now of that $23,000 you'll pay 13% tax on everything so it's really only worth ~$20,354. No wonder if rich people avoid taxes they get richer. Us poor bastards would save $10,000 a year!!!
The laws are the same for every one, and in most of the countries the tax rates for the rich are greater than those for the poor. Some people manage to pay less taxes, as they prepare their tax returns intelligently.