The fake fragrance industry is huge, just check out any local swap meet in your area.

Basically there is no way that ebay sellers will be able to consistently provide "new in sealed box" fragrances for a fraction of the retail price.  A clever reseller may occasionally get lucky buying liquidation overstock, but otherwise the fragrance is guaranteed to be fake.

If you buy any fragrance on ebay, take the bottle to a local retailer and compare it carefully to their sample bottle.  If it is identical in EVERY respect, you got lucky.  But more likely, you will spot subtle differences.  The bottom line is that the Chinese counterfeiters are TOO STUPID to do all their homework right.

Unfortunately, ebay doesn't give a rat's pitoot about these illicit merchants.  Ebay survives on fees from sellers, legal or illegal.  And most counterfeits are not detectable unless you compare them closely with a known authentic product.

Best to stay away from eBay fragrance merchants, especially if the prices appear too good to be true.

One example is the seller "heratcity."