is there any special requirements for shipping coins to US

[marnotom! · Accepted solution]

Technically speaking, unlike mailing within Canada merchandise mailed out of the country can't be sent as a letter, so you'll have to mail the coin as a small packet or tracked packet which is much more expensive than a letter.  As the item is merchandise, you'll also have to complete customs documentation for it on the buyer's behalf.

Sometimes, sellers of small, lightweight items such as collectors' cards and coins get away with sending them as letters without a customs form.  It seems to be a matter of chance whether or not they get intercepted in the mailstream and returned to the sender.

[femmefan1946 · Accepted solution]

I'd be more cautious with shipping coins in particular to the USA.
Not only are Americans in love with tracking, the demographic of customers is less trustworthy than, say,stamps.

I've rarely attended a stamp show that had any noticeable security, but when we share a show with coin dealers the organizer hire security guards.

[marnotom! · Accepted solution]

In general, yes, @femmefan1946. If @polishpr46 is referring to one of their current listings, though, the most expensive coin they're currently selling is C$20 and probably not of much interest to most US collectors.