I lucked out earlier this summer and was the first person to respond to this lady's Facebook Marketplace ad for a nice price on a Doctor Who. I flew over to her house to pay and pick up. As I was leaving, she looked at her messages and had 9 other people message to say they wanted it. Every once in a while they'll be a good price on the FB Marketplace. I've also had great luck on Offer Up and Letgo.