What I would first recommend is that you check the seller feedback and location.
If the seller has a history of selling this type of product and they have good feedback reviews, you can more likely trust them.
If the price is so low that it is unbelievable, it probably is too good to be true.
A lot of fakes come from outside the USA and are priced super low (shipped from outside the US) and that might be an indication that it is not authentic.
eBay has been working for over 25 years and most transactions go off with no issue. However, you are wise to be cautious.
