According to the Sun Valley postmaster, I have been doing it all wrong over the years. It is not a butterfly and a regular stamp, but a small packet rate of $7.35 per mailing. That comes with tracking, same as a small packet would be. I'm going to start charging that rate come January 1 2026. Alternatively, I will NOT mail out chips to buyers, you can make your own arrangements if you believe there is a cheaper way to do it.

One possible way concerns the dimensions of the mailpiece. Apparently a square envelope can still be sent at a lower cost. To do this, you will have to cut down the typical rectangular 8 X 10 business envelope and seal it with tape or something. Unknown if the USPS will accept such mailings. I'd heard once that envelopes sealed with tape will be rejected.