The problem with that is that it's regressive and hurts those who earn less. Let's say sales tax is 10%. If I'm a high earner and buy a cheap Android for $50,

The problem with that is that it's regressive and hurts those who earn less. Let's say sales tax is 10%. If I'm a high earner and buy a cheap Android for $50, the $5 I'm paying in sales tax has a much lower impact on my budget than it does to someone who earns less than I do and wants to buy the same phone.