That's good information, ladies. I will look into the flat rate priority, Oksewnsew. And, jaba, I like the idea of a roll of tracking numbers! I go to the post office to mail, so it's not really necessary, I guess. They put a tracking number on all my packages.
I sometimes think it depends on who is working at the window. When I first started swapping, I would ask the same questions every time I went in. Just to make sure I was getting the right information. Now they know what I want when I go in ... it took a while to train them!