Nordstrom Rack takes up to 85% off a selection of men's and women's designer sunglasses. (Prices are as marked.) Shipping adds $7.95, although orders of $100 or more receive free shipping. A couple of best bets:
Burberry Men's Tailoring the Mr. 56mm Square Browbar Sunglasses for $99.97 (pictured, $195 off)
Gucci Women's 53mm Modified Square Sunglasses for $149.97 ($110 off)
There are many ways to get cheap and even free services and goods after reaching a certain age.