AzWhoFan, thanks great information and you are correct, however small footnote unrelated to the Rick.
I purchased a vintage instrument and I had to pay duties, looking back at the information there is a stipulation (from the web site below).
From cbp.gov
https://help.cbp.gov/app/answers/detail/a_id/375/~/duty-on-u.s.-made-goods-returning-to-the-u.s.However, the provision stipulates the goods value could not have been advanced nor the condition improved while abroad. In other words, if an item was repaired or improved, duty could be owed on either the fair market value of the labor or the item as it has been changed.
In this case AzWhoFan is correct as selling price is same or lower than list price but good to know if purchasing an instrument that has gone up in value.