Will you be sending it to a person or a company?
They shouldn't incur any COD/duty charges but if you declare over a certain amount, US customs usually requires some additional information from the receiver such as a SSN or EIN from the receiver.
If it's a fairly big consignment company like ComicLink, Comic Connect, Heritage or even MyComicShop, they won't have any problem providing the information.
Some individual may have an issue with their SSN.
I send my stuff to ComicLink via Fedex and since CL has a Fedex account, Fedex probably has the available information already to provide to US customs.
xoxo
greggy