The price of 3.086ct cushion(NPA1464) lab diamond after 25%off is $1343.25, The original stone price of 26683 is $762.03, so the price difference for changing the stone is $581.22 (1,343.25-762.03);

The new setting price is $904.46, The original setting price is $384.99, so the price difference for the setting is $519.47 ($904.46 - $384.99).  Total: $1,100.69 ($581.22 + $519.47)

$550.345 for 50% and $550.34 for the balance 50%.

The repair center has confirmed that there is a quality issue with the 26683 stone and can replace it for the customer to remake