Nar-tar is a colloquialism for Eggs of a Narti. It is a delicacy on Nartor, as well as Cradle and other planets. The term Nar-tar is considered crass by some Planets' standards.
Generally, an ounce (about 12 eggs) of Nartar costs 50,000 Space Dollars, but it depends on various factors, such as the source, the health, the freshness or age, the location, and even the packaging.