priceless

Synonyms: beyond price cherished collectible costly dear expensive incalculable incomparable inestimable invaluable out-of-bounds out-of-sight prized rare rich treasured valuable valued without price worth a king’s ransom worth its weight in gold

Antonyms: cheap replaceable useless worthless

Synonyms: absurd amusing comic droll hilarious humorous killing rib-tickling ridiculous riotous scream sidesplitting

Antonyms: grave serious