You can also avoid sales taxes by not buying. Like a sales tax, it's a tax you have to pay it you really want to buy the thing
If you live outside the US, however, you can probably get away with this as the total value is likely under the customs exemption threshold, or if you use the device for a bit before you get on the plane, you can claim it's "used".
As a Washingtonian, I would always list and pay use taxes on my purchases from the Portland Apple Store cough if I ever shopped there before.