My tips for spotting potential fraudulent sellers:
100% feedback rating doesn't mean much, even if it's 100+ feedbacks. Look at what items the feedback was left on. There are people who sell "Recipe for Grandma's most delicious cookies" for 10 cents and send you a text file recipe, and from those you can rack up 100 positive feedbacks for ten bucks in a couple hours. There are also "front" sellers who will sell you, say, a paperclip for a penny or ten cents; you don't really pay them but the seller marks it as paid, leaves you positive feedback, and you do the same for them in return using your other ebay account.
A seller deals in trinkets and baubles that they sold for cheap, got good feedback, then suddenly has a slew of high-end items.
Sellers photos are very inconsistent...some are glossy & nice, others are taken at the kitchen table = stock / swiped photos.
Here is a perfect example: This person bought a lot of things priced under a dollar or were private so you have no real idea, racked up feedback, and suddenly came into a pile of pricey watches...all auctions ending at the same time, by which time they have gotten paid, withdrawn the cash, closed all their accounts, and yes - you might get your money back but your credit card company takes the hit and you got nothing for your troubles. I'm not saying this person is in fact a fraudulent seller, but I wouldn't be surprised if that's how these auctions turned out. Being in Thailand doesn't make them any less suspicious. I found them when looking for an Audemars Piguet 18k watch - was contemplating a bid on theirs because $199 start bid is cheap as hell....when I said "hold up, let's read those feedbacks first." Looked at other items for sale - Omega Speedmaster?? Tag Heuer Carrera?? From a guy who has been buying phone charms and shit? No way...
Too good to be true always is. Not usually - always.