Silverfish, for the love of God why put yourself through all this trouble? You wanted advice? here's mine - STOP crossing the border to ship. If your ability to sell on ebay or your profit margin hinges solely on the ability to ship from within the US then you may want to reconsider some things about your business. If its just an added incentive that may bring the occasional higher bid then thats another story. People frisking you, ripping apart cars, grilling you under the hot lights - what the heck is this? an episode of Law and Order? I've got WAAAYYY too much to worry about in life to add interrogations and being criminalized to the list.
I sell clothes myself and have done so for many years on and off ebay, and if the people really want it, they will come. Hell, if they want it bad enough, let them drag their own asses across the border, come to my doorstep and ring the bell. I'll be more than happy to oblige. Otherwise they're gonna have to have it shipped to them.
I try to save as much as possible in the expenses it takes to ship, offering free shipping every once in a while (with a slight mark up), flat rates, knocking a few dollars off shipping here and there, etc, etc - whatever it takes. But being humiliated for an already largely unappreciative customer base - sorry jack, ebay does enough of that for me already, thanks. If it works for some people, more power to ya, but for me, living an hour away from the border, and "Homeland Security" are enough to turn me off.