I think there are many factors taken into consideration when the prices of eyeglasses are determined. It is hard to tell which part of a pair of glasses is more expensive. Even with same material, different brands have totall distinct prices. To buy cheap eyeglasses with good quality, I recommend you to shop on line. I always shop on line for everything, clothes, shoes, sofa, wall paper and of course my eyeglasses. As technology develops, more and more people prefers to shop on line for its convenience and better price. These on-line shops provide various brands, styles, qualities, levels and colors of eyeglasses. You can return the glasses if you don't like it after received. It is really convenient. Click and it comes. Have a try and you will love it just I do. There are some promotions sometimes that you can have a free piece. Good luck.