You’ll see them go up for prices like that occasionally around here on OfferUp from people who just want to get rid of them or don’t know any better, but you’re more likely to encounter them beat-up and overpriced on FB Marketplace.
Last week, I managed to get a rough-ish MM80 for $120 and a decent Sarengeti Badger 100 for $120. Neither run, but I swap bigger engines in anyway. Believe it or not, you can get $30 or so out of those little Chinese engines if they fire on starting fluid, but $100 is just silly, lol…