Have you registered a business for the purpose of selling buttons? Will you be declaring the money you make selling them for income tax purposes? Are you charging tax to residents of your state? (you have to be registered to do that anyway).

Then it's not a commercial business and therefore not a commercial sale. No commercial invoice is required.

I hate to see such hobby projects get so complicated because people get wrapped up in beurocratic "process."

Tman, if the package gets lost in the mail you're likely screwed regardless of the amount declared for customs. Canada post and US Post have an automatic $100 coverage on small packets. The customs value is not the same as the insurance value. It's possible to ship something as a sample that costs $1000. It has that value to the originator even though the recipient may not have paid anything for it (and may have to return it). Incidentally, last I recall this covers breakage only - if it's lost, it's lost and gone. But I could be wrong on this - I've only ever had to make claims with courier serives.

Bruno