value has 15 distinct synonyms spread across 6 of its 11 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a numerical quantity measured or assigned or computed
“the value assigned was 16 milliseconds”
the quality (positive or negative) that renders something desirable or valuable
“the Shakespearean Shylock is of dubious value in the modern world”
the amount (of money or goods or services) that is considered to be a fair equivalent for something else
“he tried to estimate the value of the produce at normal prices”
relative darkness or lightness of a color
“I establish the colors and principal values by organizing the painting into three values--dark, medium...and light”
fix or determine the value of; assign a value to
“value the jewelry and art work in the estate”
hold dear
“I prize these old photographs”
Synonyms, antonyms and the broader and narrower relations for value come from Princeton University’s WordNet. Full sources and licences.