$20 a pair of the frames already are special price, but with the lens after this pair of frames has finally become converted into $10. The discount glasses is really very cheap. Although the prices are clearly labeled, in fact consumers are free to request a discount.
Consumer asked: “How much is the lowest this pair of frames?” A saleswoman told you: “$12, this is the price after discount.” Consumer also asked: “How much of the original price?” The shopkeeper replied: ” the original price is $30, and now very affordable, if you choose a good lens we will offer you more discount. ” (more eyeglasses…)