Even if the seller on Ebay has good reviews, I would still be very cautious. The way these scams work. it can take weeks or months for the device to show up as being non-payment in the carrier's system (or the person can just wait to report it lost or stolen). I bought my Note 3 from Swappa in November and it wasn't blocked until late January. If you do some searching, you might find some threads that help you stay safe, and tell you how to reduce the risk of getting scammed when using Ebay, but for me the risk is too high now. Once you get burned, it just sucks balls and you never want it to happen again.