A high-end watch is initially marked up by 50% above its cost price. During a sale, it is offered at a discount of 20% on its marked price. However, a special customer receives an additional discount of y% on the discounted price, bringing the final selling price to ₹4320. If the shopkeeper still makes a profit of 8% on the cost price after all discounts, what was the original cost price of the watch and the value of y?