is it in use in modern times?
Yes, in works like "Crime and Punishment", "Henry IV, Part 2",and  "Treasure Trove".
Thirty pieces of silver
 In Dostoyevsky's "Crime and Punishment", it is echoed in the 30 roubles which the character Sonia earns for selling herself. In the folk-song "King John and the Bishop", the bishop's answer to the riddle of how much the king is worth is 29 pieces of silver, as no king is worth more than Jesus. In Shakespeare's play "Henry IV, Part 2", the mistress of Falstaff asks "and didst thou not kiss me, and bid me fetch thee thirty shillings?" The story "Treasure Trove" by F. Tennyson Jesse relates the rediscovery in modern times of the thirty pieces of silver and how they drive men to kill in varied forms including murder, manslaughter, homicide, euthanasia and suicide.
what would 30 pieces of silver be worth today Between $185 and $216 . what does it refers to actually? It was the price for which Judas Iscariot betrayed Jesus. how is it referred in literature? The phrase "30 pieces of silver" is used more generally to describe a price at which people sell out.
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Thirty pieces of silver [SEP] Literary references
The 30 pieces are used in Christian literature on the betrayal of Jesus, as in the poem "Thirty Pieces of Silver" by William Blane: "Thirty pieces of silver" Burns on the traitor's brain; "Thirty pieces of silver! Oh! it is hellish gain!" or as in the poem "Matthew XXVII:9" by Jorge Luis Borges: The coin fell on my hollow hand. I could not bear it, although it was light, and I let it fall. It was all in vain. The other said: "There are still twenty nine." The phrase "30 pieces of silver" is used more generally to describe a price at which people sell out.