I wouldn't buy batteries there for sure, and probably not a mod. But ce4s? No problem with me.You have to be careful there. A lot of counterfeits and fraud does happen. I got burned once. I'm not saying never get anything from ebay, and some manufacturers even have stores, which appear to be totally legitimate. It's just a matter of doing your research, but if you can find another way to purchase them, I would probably recommend that.
Anna