I have two, NOS in-the-box Shimano 6-speed Dura-Ace EX 13-23 cassettes. Brand new, mint condition, even the boxes are in excellent shape. Dealers typically ask around $55 for these when they're available. Mine are priced at $35 which includes delivery within the U.S. International delivery for $6 each or $8 for both. I am Paypal friendly. Many thanks.
Chelsea, Michigan USA