The original selling price is $44.96
Taking 75% off results to $11.24 (which should be the correct selling price)
But Cliff took 25% off after taking 50% off the original price
Taking 25% off results to $33.72 and taking another 50% off results to $16.86
The customers are overcharged by $16.68 - $ 11.24 = $5.62