1998 United Nations New York Full Sheet of 32-cent Endangered Species Stamps. These are Mint, Never Hinged, Michel # 767-770, Scott # 730-733.
For First Class, flat shipping with a stiff cardboard backing for mint sheets I charge a flat rate of $4.00 for items purchased with one payment and sent to US Addresses. That covers as many sheets as you win, so bid on several and save on postage.