Euch,
Each set of(the 10) these strikes could go. USPO cardboard flat rate piority mailer for $4.05. OR piority box if you prefer for $8.10.
The way it has worked great for me so far is:
I get a used bubble mailer that fits in the flat rate cardboard mailer. I tape the strikes to a piece of card board(to keep them from sliding around inside). Sometimes I put strike(s) in a foam or cardboard cover, before taping good. Put this card board with strikes on it, inside the bubble mailer and seal it somehow. Be sure to put name and address on bubble mailer; just in case needed.
Put bubble mailer in the addressed USPO mailer and seal. Add insurance if you want. And away they go.
Dan