i’ve brought and sold a few bits on the classifieds, never had any problems.
i work to this buying and selling.
new never used= half of retail + 10/15%
last years model= half of retail
2 year old= half of retail – 10/15%
obviously there are exceptions, rare or hard to get bits go for a little more.
but there are plenty of tyre kickers and low ballers on here! as well as sellers with unrealistic prices!