Yes. There are also second-order effects at play here. Buying these materials second-hand may normalize their use, or even contribute to fashion trends, which may make other people more likely to buy those materials first-hand. This would of course result in financial support for the leather and fur industries. That said though, these second order effects are very unpredictable and hard to measure, and their strength would vary a lot person to person, depending on how influential someone is.