You say not to recommend craigslist, but a quick check yields many results in NJ-PA. Any moped listed in your price range will sell usually in a matter of minutes, so you have to watch craigslist often and be ready to jump on it. Search "tomos moped - $300 (manheim). Also https://www.mopedarmy.com/forums/read.php?2,3109142
https://www.mopedarmy.com/forums/read.php?2,3109144 (edited)