I guess common sense is not your strong suit.
So, let’s see: I don’t want to buy a book in Texas because the sales tax is 8.25% but I can buy it in some other state at a rate of 6.7%. Do I save money? Let’s see...
The book costs 15.00. The sales tax in Texas is $1.2375. The sales tax in the other state is $1.005. That’s a savings of $.2325. So, you save 23 cents but shipping to you costs $7.00. HOW MUCH MONEY DID YOU SAVE?
No need for the "common sense" insult. We're just talking here.