Well, for the prices, there is nothing for you to worry about. As far as I know, the chain sunglasses are not expensive and only cost $13. And it also has some discounts on the online shop. For example, you can buy them on sunglass warehouse. And just link to the website as soon as possible, maybe you have the chance to give the service. http://www.sunglasswarehouse.com/swovvist5.html
And also, the chain sunglasses are very beautiful, so they are popular by many famous people. The chain is attached to the frame and can wear around your neck, or loose in the front. So it can just make you feel comfortable. Just buy them right now.