This isn't always easy to find and I came across a thread earlier today that made me think the seller didn't realize they didn't need to accept a normal PayPal payment (or PayPal at all) to use their shipping.
https://www.paypal.com/us/cgi-bin/webscr?cmd=_ship-now. Just login and ship. No linked transaction needed.
EDIT: Since other options have been listed that seem to offer easy and cheap shipping without dealing with the devil that is PayPal I'm listing them here as well.
https://www.pirateship.com
https://goshippo.com
https://www.paypal.com/us/cgi-bin/webscr?cmd=_ship-now. Just login and ship. No linked transaction needed.
EDIT: Since other options have been listed that seem to offer easy and cheap shipping without dealing with the devil that is PayPal I'm listing them here as well.
https://www.pirateship.com
https://goshippo.com
Last edited: