Anyone who sells them normally, will have them. Including the Post Office. While the USPS is a Federal Agency, it is a self sustained Govt. Agency, and is not impacted by the shutdown.
That there's pretty funny. $6B loss expected this year.
Sorry I didn't word that to meet your standards... USPS is a failing agency, agreed... the numbers prove it... however, they are not at the mercy of shutdowns.... savvy?