be at a premium
if something is at a premium, people need it or want it, but there is little of it available or it is difficult to get

[TahlilGaran] Dictionary of Contemporary English ▲

at a premium
1.
not easy to get.
During the negotiations, sleep was at a premium.

Usage notes: usually said about something that is highly valued because it is hard to get
2.
for a higher price.
It's possible to get a large apartment, but only at a premium.

[TahlilGaran] English Idioms Dictionary ▲

at a premium
at a higher price than usual because of something special
The tickets for the final basketball game were selling at a premium.

[TahlilGaran] English Idioms Dictionary ▲

at a premium
adv. phr. At a high price due to special circumstances.
When his father died, Fred flew to Europe at a premium because he had no chance to buy a less expensive ticket.

[TahlilGaran] English Idioms Dictionary ▲