My local postmistress conveyed the following to me today:

The 12¢ surcharge is only applicable to the first oz. (Thanks to those who corrected me on this).

So, to mail one chip first class anywhere in the US with bubble mailer is 49¢ (37¢ + 12¢ surcharge).

Two or more chips up to 2 oz is 60¢.

I mailed two chips to Canada today. I had to fill out form 2976 and declare the contents and their value. You have to pick up this form at the post office as it's not available online.

To ship two chips to Canada is 85¢, which is airmail. They no longer have ground service for letters to Canada.