I’ve found a couple of pins on Facebook Marketplace in the last few years, but lately the quality of their search results has nosedived significantly. There’s a lot of irrelevant results from partners, paid listings, and online retailers polluting the stream. Even when there’s a game nearby (in the same zip code!) I have to scroll down significantly to find it. Notifications have never worked right or tipped me off to anything good. Everything I’ve found has just been dumb luck and good timing.