Maybe I can help with the shipping questions. :)
You can order Priority boxes, envelopes, labels, etc. at the post office's website, if your local post office doesn't have what you need. Some post offices are well-stocked, and others have very few supplies. The shipping supplies are free, but there is usually a minimum quantity, like 10 or 25 boxes or labels. (Use one now, and save the rest for later. ;) ) They do offer envelopes with pre-paid Priority Mail postage (those aren't free, of course). Here's a link to the USPS supplies page, and also a link to their postage calculator (might come in handy):
Supplies (You may have to copy and paste it into your browser. It's a secure link, which sometimes doesn't show up as being "clickable" on chat forums.):
https://shop.usps.com/webapp/wcs/sto...0001&langId=-1
Postage Calculator:
http://www.usps.com/tools/calculatep...lculatepostage
You can also print Priority Mail postage from the USPS website at
http://www.usps.com I believe it's considered "metered mail", so check with the swap hostess before printing a return shipping label. Some post offices balk if the date or origin zip code is off.
For those of you with PayPal accounts, you can print Priority Mail postage, First Class postage, and several other ones by using the link below: (You may have to copy and paste it into your browser. It's a secure link, which sometimes doesn't show up as being "clickable" on chat forums.) Again, check with the hostess before printing a return shipping label this way, as I believe this is considered "metered mail" too.
https://www.paypal.com/us/cgi-bin/webscr?cmd=_ship-now
If you stick a Priority Mail label on a First Class package, you'll be expected to pay the Priority Mail rate. If your post office happens not to catch it immediately, chances are it'll either be returned to you for additional postage, or it'll arrive at its destination with postage due from the recipient. You also can't use Priority Mail boxes or envelopes to ship via First Class. They'll expect to be paid the full Priority Mail rate. (Nope, you can't flip the box inside out in order to pay less postage. People used to do that, but now the boxes are printed on both the inside AND the outside. :lol: )
Hope this helps. :D