I usually have really good experiences with the well-known sellers on IG (@cocoapproved, @lovelotsluxury, @timelessv0gue, @chlcouture, etc.), but one noticeably bad experience. Hopefully this will be helpful.
I bought a Trendy CC from @luxloversmelb on IG that was described as excellent condition. She said the only wear was "only minor rubbing on one corner that's size of a dot. Hardly noticeable. Also a minor rub at top right. I'll send a pic. Both inevitable and expected as there is no perfect preloved trendy." Then she sent a picture of the bag and the corner, saying "the corner rubbing is so fine I can hardly capture on pic." She also said that the bag "hasn't been used much for a trendy." She was super friendly and responsive, and shipping was fast as well (I was charged $75 for shipping).
However, when the bag arrived, I was so, so disappointed. There was a loose thread on the back, there were several scratches on the leather all over the bag (they were faint, but they were still there), the back pocket was stretched, the metal plate was quite severely scratched, the turn lock had tarnishing, and the interior had what looked like crumbs in it.
I know other people have had good experiences with them, so maybe this was just a one time mistake, but I was left feeling like I was duped.