US tax rates

[the deceived]

Wow! I didn't realise that they charged you tax when you got to the counter in America! Is the same on say Newegg and other websites from the US? Just wondering because when people ask for help on a new system and they are from the US, I use Newegg as a good price estimator, and well if they add tax on the end to your total price, then I'll keep that in mind for future suggestions and help