Consider before bidding on high-end watch brands.
When I started manufacturing watches in the late 1970's, the differences between authentic watches and 'counterfeits' were much more obvious. Even a beginner (as I was then) could spot the fakes from a distance. Today, it has become much harder. The reason for this is that most of the well known watch companies buy the majority of their components from China. EVEN THE SO CALLED 'SWISS' ONES. Of course, the Chinese technical abilities have gone through the roof in the past 25 years. However, the 'Swiss' brands have also lowered their quality standards and the result is often counterfeits, which are nearly identical to the authentic originals.
If you suspect you are bidding on a counterfeit, you can do three things:
a. Don't bid very much. Its not exactly legal to buy a counterfeit knowing it is so. Suspecting it is so is not against the law. Often, you won't have to pay very much to win and then, you can't get badly hurt, even if the watch turns out to be a fake. If it is real, all the better.
b. Bid as if the watch is authentic and then, make sure not to care if you turn out to have been taken. If you think its real, and it looks real, you can always pretend it is real. (Not recommended).
c. Do your best to deduce if the seller is legitimate and knowledgeable, before bidding (recommended). If the seller trades in many types of products, in addition to watches, they may not have the expertise to correctly evaluate a watch. Should that be the case, the seller may have a great feedback rating but be unable to correctly authenticate a watch. Also, the years of membership are at least as important as the total feedback score. Example, someone who is an eBay seller for 5 years with a modest total feedback number and a 95 positive (or better) rating, may be equal (from an overall trust perspective) to a 1 or 2 year member, with an overall feedback number that is much higher. Generally, a factory gift box is a good clue if the product is authentic. Believe it or not, it is harder to counterfeit gift boxes then it is to copy the watches inside. If a new watch comes without a gift box, this can be a warning sign. The box should match those gift-boxes known to accompany that brand of watch. If you are bidding on a high-end brand, you may wish to visit your shopping mall to eyeball the same watch in its environment, look at the box and warranty, etc. The eBay seller will generally show a photo including the gift box, especially if it is a high-end brand. Typically, low and medium-end brands are not counterfeited (examples include Bulova, Seiko or Citizen). This is because it costs the same to build a counterfeit Rolex, Omega or Vasheron, etc.. Exceptions do exist.
Last tip- Don't pay too much attention to the local (Main Street) watchmaker in town, UNLESS YOU KNOW HIM OR HER QUITE WELL. Often, these merchants are frustrated because everyone else in town can sell watches (including the beauty salon) but not them. So they make it a habit to misrepresent evaluations, in hope of luring you to buy from them next time. For the same reason, you should think twice before even having a battery changed in a small watch store, without positive references or previous personal experience. The high-end mall store can be as economical for battery changes and usually less apt to shove a screwdriver into a perfectly good movement and then call it 'defective' or even 'counterfeit'.