This is the jest of your links:
If you bring items that you received free as a gift into the U.S. from Canada, you must give a $ dollar amount that you believe the item is worth. Because you may get an exemption or reduced a duty rate.
If you are bringing items that you bought in Canada, into the U.S., you must provide proof of purchasing these items with a store receipt, an invoice, or a bill of sale AND you must declare them on a Customs and Border Protection (CBP) declaration CBP form 6059B. Link to Form:
http://www.cbp.gov/travel/clearing-cbp/traveler-entry-form
If you are bringing items that you bought from Canada into the U.S. to SELL then you must contact a Customs Broker to make arrangements in advance to have your goods cleared through Customs and Border Protection. Use the link below to contact that port:
http://www.cbp.gov/contact/ports
Ask about Goods and Services Tax (GST) is a value-added tax introduced by the Federal Government in 1991 at a current rate of 5%.
And Ask about Harmonized Sales Tax (HST; combined GST and provincial sales tax), which can range from 12–15% on top of the GST, making it a total of 17%-20% in Taxes!
It appears Michigan was the only state in U.S. to use a VAT.
Also, they said if you travel with your personal items such as a blow dryer, it should appear to be at least 2 years old to avoid having to pay a duty rate lie you would a new hairdryer.
So, anything new may require you to pay a duty rate.
That’s all I know, so please make that phone call. :)