Unless I'm mailing from my own zip code or doing a DIM weight shop, I mail packages to myself. From my own zip code, I mail to my sister and get the box back from her. For a DIM weight, I ship to a friend three states away. (I used a DIM weight shop to mail her an old Ipod recently -- probably the most expensive postage ever spent on a three ounce, 2x2 inch item ever.)
I tape all over the face of the box twice, then peel the Priority labels and postage label off and just reuse the same box. The second layer of tape allows you to remove labels that won't peel off nicely. Peel off the tape, put new tape, and you're good to go.
Time to build a bigger bridge.