Make a Store, to make mass orders or a section to sell this stuff( easier to follow when it's in it's own section/sales like those sell your mass marketed stuff
I live in Los Angeles, where you think most your clothing comes from? I can search around Downtown LA to see how much a shop would charge to amke Hoddies with custom decals on them, i can prolly find a Vinal shop too taht will make the stickers, but there has to be buy-in 1st before anything will happen, Don't wanna go broke right off the bat!