I heard that the Nine West website do not list any sunglasses. They just collect other brands sunglasses but labeled as as Nine West. I just search their sites and find the prices of the sunglasses on Nine West are different. You can get the cheapest sunglasses from there with less than $50. But you may spend more than $100 to buy expensive sunglasses.
Well, first, I think you do not need to worry about the prices, for they are very cheap to buy. So just pick the ones you like. And choose the best styles. In my opinion, the most important thing you should pay attention to is buy real ones, so just buy them on some big online shop, such as yahoo, shopping. Link to https://shopping.yahoo.com/sunglasses/nine-west--brand/, and you will find many different types and they also have different colors and prices, it all depends on your own choice. Generally speaking, you can just pay 40 dollars to get one pair. Of course, there are also some high prices.
I should tell you that Nine West is an American brand which used to focus on making leather shoes and is one of the largest retailers of fashion goods in America. Later, they began to produce other accessories such as sunglasses. If you are planning to buy a pair of them, you should get about 200 to 400 dollars. I think their products are basically affordable.
They are not very expensive if you buy one from the online store. You may go to the Overstock.com which the nine west sunglasses are sold at different kinds of materials, frames and styles. These sunglasses are from $40 - $45. If you want to buy one, you could go to have a look.