Till this:
"We will NOT ship via US Postal Service, not even a button."
Evidently the owner doesn't realize the UPS WILL CONTRACT with USPS for delivery. When I drove for Fed Ex ground LOTS OF TIMES I delivered to the local post office for them to do local delivery.
And a small, flat rate box is less than $6, the box is free and is tracked from shipper to delivery. If ATF doesn't think $4 is a big deal then he should charge $4 less for shipping... 'cause, $4 is not a big deal... until it come out of HIS pocket.