Buying Microphones on Ebay

I have now bought SM58 microphones twice on e-bay and twice refunded because they were fake. The conclusion to me is that if there is a new bargain on Shure SM58's the only thing you can be 'sure' of is that they are dodgy. Shure maintain a pricing policy in the USA, not legally maintainable in the UK but I am certain they will have their methods. 
The good thing about buying on e-bay and paying with PayPal is the buyers protection. In the first case I had bought 3 SM58s that turned out to be fake. There are plenty of websites that advise how to identify a fake SM58. The weight, the numbering on the pins of the XLR plug (often no numbers on the pins of the fakes) etc. PayPals conclusion was that I got a refund and must destroy the fake mics.
On the 2nd occasion, after winning the bid and paying, I noticed the same seller had sold a number of SM58s saying it was hardly used and to all intents and purposes a cut and paste. He used 2 different photos but the wording was identical on all. I then asked if he was sure they were genuine Shure product and related my previous experience - of course highlighting the destroyed mics. I had a refund by morning.
In fact the fake mic problem is not just the Shure SM58 but also the SM57 and a number of Sennheiser mics and earphones. These come fully branded, boxed and with all the paperwork - but they are still fake. If you fall victim to this you have full legal rights to get a refund but potentially could also have both the police and customs and excise on the case - though they probably would not be interested in small quantity counterfeit products.
With these microphones, probably if the price is too good to be true (50% - 70% of the new price) then it's wrong.