Compared with common sunglasses, the price of prescription sunglasses must be a little higher. But about the exact price, it is hard to define because of the price range according to different types of eyeglasses. About the rx sunglasses at walmart, they are cool. If you want to look fashionable, you could have a try. And the price in walmart is relatively cheap. You should take the relax to choose the suitable one.
I have searched Walmart online, the prices of those prescription sunglasses at Walmart ranges from $15.25 to $78.00, which are from Vision Departments.
P.S. You can print coupon from Walmart Vision Centers online and bring it in to your local Walmart Vision Center for a free lens cloth and cleaner.
Here is the address: http://www.walmart.com/cp/Walmart-Vision-Centers/1078944
Hope you like it!