The listing, United Nations postal card #UX3 has ended.
United Nations (New York)
Postal Card #UX3
I have several of these available; the scan is representative of what you will receive.
Postage with untracked 1st class mail is free within the USA (tracked is additional at $2.32), foreign destinations are $1.60 for standard airmail (PayPal accepted).
My general terms for stamp-related Listia lots can be found here (please read, it answers a lot of basic questions):
http://listiarules.webs.com/