Over the last several weeks I have bought and sold two dozen lenses as part of my transition from Canon to Sony. Because I mostly acquire used gear, I was able to make the transition with little net outlay.  I often sell lenses for more than I paid for them. I know the market well and never overpay on the buy side. When it comes time to sell, I clean the lens thoroughly and take the time to make compelling marketing photos for my listings. The same cannot be said for camera bodies which depreciate rapidly when obsoleted by newer versions. For those who are wondering, I took the picture with my phone.