At a higher price than usual owing to scarcity; also, considered more valuable, held in high esteem. For example, Since that article came out, the firm's stock has been selling at a premium and Space is at a premium in most stores. This idiom uses premium in the sense of “bounty” or “bonus.” [Mid-1800s] Also see put a premium on.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.