First time seller. I had 100 coffee mugs made and plan on selling in my shop on Big Cartel. I didn't realize how pricy it would be to ship and should've done some more research prior to printing. I'm looking into the most economical way to ship these, and the general consensus is that the USPS flat rate boxes are the way to go. However, using these boxes puts the shipping price higher than the product itself (shipping is $13-15). Has anyone found a better alternative for shipping coffee mugs? I don't want anyone to think I'm ripping them off nor do I want to have a price so steep it deters potential customers.