You have to check the usual sites (Facebook marketplace, eBay, autotrader, gumtree) several times a day and be prepared to travel quickly for a good deal. Deals do exist. A couple of days ago I sold my YBR 125, 2016, 5k miles, really excellent condition, for only a little above your budget. Sold to first person to turn up and I priced it a little lower than competition for an easy sale.
I bought and sold mine on FB marketplace.
Check several times a day and move fast. Be prepared to travel. Good luck.