Well, as you can see, Valentino is a well renowned fashion brand which was founded by Valentino himself in Italy. The brand has always been looked as a leading role in the fashion circle, with its prime quality and impressive design to be honest. To get them, you can try to pay a visit to some large shopping malls in New York or LA. They are indeed expensive, could be over a grand per pair of sunglasses.
You can search them online. I just have a try and find several sites where provide valentino sunglasses. But their prices is a little expensive. Most of them need hundreds of dollars. I even see a pair of valentino sunglasses prices over $500. Lucky, there are still some of valentino sunglasses sold over 200 dollars. Here is a websites, you can check yourself: https://www.bestbuyeyeglasses.com/valentino-sunglasses.html
If you want to buy the valentino sunglasses, I suggest several places for you to go and have a search, like the walmart, visionwork, amazon and ebay. They are not very expensive when compared with other big brand ones. The average price is about $ 80. If you want to buy the better one, you'd better prepare more money.