I sold them some 20+year-old stuff (Meridian and Classe). The process was very easy - they send you a FedEx label and all you have to do is pack it up safely. I was very happy with the process.
I thought the prices they offered were fair. Yes, you will be offered a wholesale price and you will certainly make more selling it on your own.
You are giving up some profit in exchange for not going through the hassle of selling. What is that worth to you? I can save money by mowing my own lawn, but I pay someone else to do it because I have better things to do with my time.