With my experience of recently receiving a pair of fake Hot Pink GHD's, I would now ask seller to provide the serial number on the label attached to the cord and verify this with customer services at GHD before buying or bidding! Apparently it is quite in order for the serial numbers on the label and the actual item to be different but it is the the number on the label that matters.
I am sure giving the amount of fakes flooding ebay at the moment that we are well within our rights to ask the seller to provide this information and if he/she is reluctant to do so then your question is answered and do not bid.
I have since contacted several sellers asking them to provide the serial number as authenticity and only one has been able to do so. I had replies like, sorry all packed up and ready to send, sorry, the tag fell off and I lost it, or if in any doubt do not bid!! Paypal are not very accomodating when a fake item is sent. I am still waiting for an outcome and that's been since early April. They now require me to send the item to GHD in order to have written confirmation of the item being counterfeit which will cost me more money again sending them off so reckon I'm just counting my losses and will be more careful in future when making purchases on ebay.