Since the USPS will deliver a padded envelope for 86¢, but they may take a second look at the "package" if they see postage stamps, just use the self-service scale at the USPS and print out an 86¢ metered stamp. They tend not to scrutinize the package if it has one of those electronically scanable stamps. Will save you a lot over the course of a year -- money that can be put into your collection rather than the pockets of the USPS.