as far as i know in the market price ingame.
kantata pair +5stam low dura = 40-45rows
high dura = 45=50rows
kantata pair +10 stam low dura = 50-60rows
high dura = 60-70 rows max..
based on the market price ingame.. but its up to the seller whether he sell rush(which means low price)
or not in a rush (which means OP seller). hop this will help you