I personally have run across this amazing website and then got one there. Not quite awesome about their delivery service speed but does save you approximately 76% and delighted for this. The quality is good and till now not spot a issues.
Fake branded glasses such as a Oakley's is common as they are very popular. Its hard to say if the website selling these fakes is legit and will actually send the glasses, but I will say that most websites are built with Zen-cart and is registered to a Chinese company/person. Your best bet is to use well known websites like ioffer and alibaba. I would not recommend fake brands as they will be very poor quality and actually look fake.