It's always tempting, when you see a pair of "Brand Name" sunglasses at rediculously low prices, to bid on them. I have found several web sites which openly sell Fake Oakley, Police, Ray Ban etc for as little as $20 per dozen. Many of these glasses, I see advertised on Ebay by people claiming them to be genuine when they are in fact far from it.
How to spot the rouges. Anybody stating that they are new and real but just don't seem to have the box, paperwork or certificates. Prices which just don't make sense, unverified members with low ratings.
It's not just the price. Many of these glasses have little or no UV protection, which can accellerate damage to your eyes as the lens focuses the light on you eye rather than protect it.
Funding Crime. Most fake products are produced and sold to fund illegal organisations many sellers are unwittingly putting money in the pockets of crime syndicates just to make a quick Buck.
So don't be tempted into parting with your money for a product which will damage your eyes, fund crime and prove to be a big disappointment.