Before I go to bed (at around 3 am), I usually dig around Ebay for watches. I am an avid collector. I am fascinated by mechanical watches, but will buy quartz watches, as well.
This will be the beginning of my guide. Additions will be made. I will post valuable information as it comes to me.
Ebay is a great place to find the watch you are looking for. Researching a seller's history is one of the most important factors in watch buying.
Low feedback is always skeptical. 0 feedback...good luck! 13 feedbacks; research to see what the feedback is. If the seller has been a member of ebay for 6 years and has 13 feedbacks, then email them to talk about the item. If they have been a member for 2 months, they you should assume that they are actively selling and that you will actually receive the item after you pay for it.
Low feedback may also mean that the seller does not know too much about the Watch they are selling (maybe). If they guarantee that it is authentic, then you may want to go for it and hope Paypal will back you up, if the transaction goes wrong. If the seller has 5 feedbacks, says that they know nothing about the watch, has blurry pictures, and is offering a Rolex Daytona for $400, then avoid it and keep searching!
Low feedback sellers can be heaven-sent. A lot of times the seller simply sells items here and there and offers very fair prices for their items. The best prices that I have found are from sellers with 20-200 feedbacks, who are selling one of their personal watches.
High feedback sellers, probably want fair market price for their items (like me!). A high feedback selling usually represents their watch in a fair manner. I have found awesome watches from sellers with Tons of feedback. If you are looking for a specific watch and want one that works well, no problems attached, then go with a high feedback seller.
Again, you want to view the sellers feedback, regardless of the number of feedbacks that they have. 1000 feedback with mainly watches and jewelry on the list means that the seller knows a lot about timepieces. 1000 feedbacks from a seller who sells antiques (but not watches, in particular) can yield a gem. People are buying at estate sale all the time, then listing their items on Ebay. These sellers are great! they sell a lot, know the market, and may want to just make $50 on a watch that they found. Their profit margin may still leave you with a great deal on a watch.
If the seller has 500 feedbacks, but is located in Asia, or eastern Europe, then cross reference the pictures of their watch with other, similar watches on ebay. There are a lot of Omegas and Breitlings on the market that are non-authentic. Ebay is good at searching these guys out, but the watches still make it on the site. I would steer clear of international sellers, unless they are from Western Europe. Note: Australian sellers seem to always have good prices on authentic watches!
You can find a vintage mechanical watch from China that has all of the right markings on the dial and movement, but is still a fakie. Cross reference pictures to make sure the movement is authentic, regardless of what is engraved on it.
I will add information as it runs thru my head...hope the above can help, if you are skeptical about a watch that you are looking at!
Keep in mind that you can buy a watch on Ebay, wear it for a year, then resell it! Dont think of it as "money gone", think of a watch purchase as an investment!