Sell your old car seat on Craigslist? I remembered being cautioned to buy our car seat new since you don't know what happened to someone's seat. However, I can truthfully say ours has never been in an accident, so why not sell it?
People sell them at mom to mom sales all the time and people actually buy them. It makes me cringe since you have no idea what you're getting from a stranger and that's one piece of equipment I would not take my chances with. Would I sell? Sure, because I know that I'd never sell something that wasn't totally safe but as a buyer, I'd never touch a used car seat that I wasn't buying from someone I knew and trusted. That being said, many people do not feel the same as me and do not even consider this an issue so you'd probably have no issue selling it.
Re: Would you ever...
Married: 1/2008 ~ DD#1: 3/2012
TTC #2: Started 4/2014 BFP 7/30/15 MC 8/3/15 BFP 9/4/2015 EDD 5/16/2016