I also purchased glasses from Glasses USA and they were really nice and the price you see on-line for the frames include the lenses. If you have a strong RX then you'll pay more for the thinner lenses but still not that bad. I'm waiting on RX sunglasses to come in any day from Glasses USA. Side note if you don't return your unwanted glasses within 14 days, you will have to get a store credit or if you still want a refund you will only get 80% back. Buyer beware, I learned that the hard way!!
On-line purchasing can be tricky but you want to make sure the company that you're ordering from has a NO HASSLE return policy. Those glasses you ordered may not look as good in person as they did on-line or they just may not complement your face. I ordered these zebra striped Jimmy Choo glasses that I was crazy over from Coastal, when I got those glasses and put them on my face they were hideous! I have not had any problem with returns from the sites mentioned above, knock on wood. If you don't like trial and error this is not for you but if your game, make sure you read the fine print.