I bought a pair of size 52 Persol 714 24/57s from eBay as I had trouble tracking down that particular combination in London. I've only bought a few things off eBay, this seller has very good feedback and seems genuine but I'm always a bit apprehensive.
Item will be delivered tomorrow and I'm assured come with 'authenticity cards'. Seeing as I've never seen such cards before they mean nothing to me!
I'm not generally mistrusting but well, eBay is eBay..
If anyone has any tips that would be great.