have: It only takes one postal worker somewhere along the path from your box to your customer's home to mess it up for you and insist on the more expensive by-the-book method.

I know this is embarrassing to have it happen and to have to deal with customers who you tried in good faith to bring lower prices. Those of us who dealt with this issue years ago have warned chip board members, yet we continue to be "outvoted" by collectors who will say they never had a problem.